lustre/llite/vvp_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 VVP layer.
  37  *
  38  *   Author: Nikita Danilov <nikita.danilov@sun.com>
  39  */
  40
  41 #define DEBUG_SUBSYSTEM S_LLITE
  42
  43 #ifndef __KERNEL__
  44 # error This file is kernel only.
  45 #endif
  46
  47 #include <obd.h>
  48 #include <lustre_lite.h>
  49
  50 #include "vvp_internal.h"
  51
  52 /*****************************************************************************
  53  *
  54  * Page operations.
  55  *
  56  */
  57
  58 static void vvp_page_fini_common(struct ccc_page *cp)
  59 {
  60         cfs_page_t *vmpage = cp->cpg_page;
  61
  62         LASSERT(vmpage != NULL);
  63         page_cache_release(vmpage);
  64         OBD_SLAB_FREE_PTR(cp, vvp_page_kmem);
  65 }
  66
  67 static void vvp_page_fini(const struct lu_env *env,
  68                           struct cl_page_slice *slice)
  69 {
  70         struct ccc_page *cp = cl2ccc_page(slice);
  71         cfs_page_t *vmpage  = cp->cpg_page;
  72
  73         /*
  74          * vmpage->private was already cleared when page was moved into
  75          * VPG_FREEING state.
  76          */
  77         LASSERT((struct cl_page *)vmpage->private != slice->cpl_page);
  78         vvp_page_fini_common(cp);
  79 }
  80
  81 static int vvp_page_own(const struct lu_env *env,
  82                         const struct cl_page_slice *slice, struct cl_io *io,
  83                         int nonblock)
  84 {
  85         struct ccc_page *vpg    = cl2ccc_page(slice);
  86         cfs_page_t      *vmpage = vpg->cpg_page;
  87         int count = 0;
  88
  89         LASSERT(vmpage != NULL);
  90
  91         if (nonblock) {
  92                 if (TestSetPageLocked(vmpage))
  93                         return -EAGAIN;
  94
  95                 if (unlikely(PageWriteback(vmpage))) {
  96                         /* Something gets wrong? */
  97                         unlock_page(vmpage);
  98                         return -EAGAIN;
  99                 }
 100
 101                 return 0;
 102         }
 103
 104         /* DEBUG CODE FOR #18881 */
 105         while (TestSetPageLocked(vmpage)) {
 106                 cfs_schedule_timeout(CFS_TASK_INTERRUPTIBLE,
 107                                      cfs_time_seconds(1)/10);
 108                 if (++count > 1200) {
 109                         CL_PAGE_DEBUG(D_ERROR, env,
 110                                       cl_page_top(slice->cpl_page),
 111                                       "XXX page %p blocked on acquiring the"
 112                                       " lock. process %s/%p, flags %lx,io %p\n",
 113                                       vmpage, current->comm, current,
 114                                       vmpage->flags, io);
 115                         libcfs_debug_dumpstack(NULL);
 116                         if (slice->cpl_page->cp_task) {
 117                                 cfs_task_t *tsk = slice->cpl_page->cp_task;
 118                                 LCONSOLE_WARN("The page was owned by %s\n",
 119                                               tsk->comm);
 120                                 libcfs_debug_dumpstack(tsk);
 121                         }
 122                         LCONSOLE_WARN("Reproduced bug #18881,please contact:"
 123                                "jay <jinshan.xiong@sun.com>, thanks\n");
 124
 125                         lock_page(vmpage);
 126                         break;
 127                 }
 128         }
 129         /* DEBUG CODE END */
 130
 131         /* lock_page(vmpage); */
 132         wait_on_page_writeback(vmpage);
 133         return 0;
 134 }
 135
 136 static void vvp_page_assume(const struct lu_env *env,
 137                             const struct cl_page_slice *slice,
 138                             struct cl_io *unused)
 139 {
 140         cfs_page_t *vmpage = cl2vm_page(slice);
 141
 142         LASSERT(vmpage != NULL);
 143         LASSERT(PageLocked(vmpage));
 144         wait_on_page_writeback(vmpage);
 145 }
 146
 147 static void vvp_page_unassume(const struct lu_env *env,
 148                               const struct cl_page_slice *slice,
 149                               struct cl_io *unused)
 150 {
 151         cfs_page_t *vmpage = cl2vm_page(slice);
 152
 153         LASSERT(vmpage != NULL);
 154         LASSERT(PageLocked(vmpage));
 155 }
 156
 157 static void vvp_page_disown(const struct lu_env *env,
 158                             const struct cl_page_slice *slice, struct cl_io *io)
 159 {
 160         cfs_page_t *vmpage = cl2vm_page(slice);
 161
 162         LASSERT(vmpage != NULL);
 163         LASSERT(PageLocked(vmpage));
 164
 165         unlock_page(cl2vm_page(slice));
 166 }
 167
 168 static void vvp_page_discard(const struct lu_env *env,
 169                              const struct cl_page_slice *slice,
 170                              struct cl_io *unused)
 171 {
 172         cfs_page_t           *vmpage  = cl2vm_page(slice);
 173         struct address_space *mapping = vmpage->mapping;
 174         struct ccc_page      *cpg     = cl2ccc_page(slice);
 175
 176         LASSERT(vmpage != NULL);
 177         LASSERT(PageLocked(vmpage));
 178
 179         if (cpg->cpg_defer_uptodate && !cpg->cpg_ra_used)
 180                 ll_ra_stats_inc(mapping, RA_STAT_DISCARDED);
 181
 182         /*
 183          * truncate_complete_page() calls
 184          * a_ops->invalidatepage()->cl_page_delete()->vvp_page_delete().
 185          */
 186         truncate_complete_page(mapping, vmpage);
 187 }
 188
 189 static int vvp_page_unmap(const struct lu_env *env,
 190                           const struct cl_page_slice *slice,
 191                           struct cl_io *unused)
 192 {
 193         cfs_page_t *vmpage = cl2vm_page(slice);
 194         __u64       offset = vmpage->index << CFS_PAGE_SHIFT;
 195
 196         LASSERT(vmpage != NULL);
 197         LASSERT(PageLocked(vmpage));
 198         /*
 199          * XXX is it safe to call this with the page lock held?
 200          */
 201         ll_teardown_mmaps(vmpage->mapping, offset, offset + CFS_PAGE_SIZE);
 202         return 0;
 203 }
 204
 205 static void vvp_page_delete(const struct lu_env *env,
 206                             const struct cl_page_slice *slice)
 207 {
 208         cfs_page_t       *vmpage = cl2vm_page(slice);
 209         struct inode     *inode  = vmpage->mapping->host;
 210         struct cl_object *obj    = slice->cpl_obj;
 211
 212         LASSERT(PageLocked(vmpage));
 213         LASSERT((struct cl_page *)vmpage->private == slice->cpl_page);
 214         LASSERT(inode == ccc_object_inode(obj));
 215
 216         vvp_write_complete(cl2ccc(obj), cl2ccc_page(slice));
 217         ClearPagePrivate(vmpage);
 218         vmpage->private = 0;
 219         /*
 220          * Reference from vmpage to cl_page is removed, but the reference back
 221          * is still here. It is removed later in vvp_page_fini().
 222          */
 223 }
 224
 225 static void vvp_page_export(const struct lu_env *env,
 226                             const struct cl_page_slice *slice,
 227                             int uptodate)
 228 {
 229         cfs_page_t *vmpage = cl2vm_page(slice);
 230
 231         LASSERT(vmpage != NULL);
 232         LASSERT(PageLocked(vmpage));
 233         if (uptodate)
 234                 SetPageUptodate(vmpage);
 235         else
 236                 ClearPageUptodate(vmpage);
 237 }
 238
 239 static int vvp_page_is_vmlocked(const struct lu_env *env,
 240                                 const struct cl_page_slice *slice)
 241 {
 242         return PageLocked(cl2vm_page(slice)) ? -EBUSY : -ENODATA;
 243 }
 244
 245 static int vvp_page_prep_read(const struct lu_env *env,
 246                               const struct cl_page_slice *slice,
 247                               struct cl_io *unused)
 248 {
 249         ENTRY;
 250         /* Skip the page already marked as PG_uptodate. */
 251         RETURN(PageUptodate(cl2vm_page(slice)) ? -EALREADY : 0);
 252 }
 253
 254 static int vvp_page_prep_write(const struct lu_env *env,
 255                                const struct cl_page_slice *slice,
 256                                struct cl_io *unused)
 257 {
 258         cfs_page_t *vmpage = cl2vm_page(slice);
 259         int result;
 260
 261         if (clear_page_dirty_for_io(vmpage)) {
 262                 set_page_writeback(vmpage);
 263                 vvp_write_pending(cl2ccc(slice->cpl_obj), cl2ccc_page(slice));
 264                 result = 0;
 265         } else
 266                 result = -EALREADY;
 267         return result;
 268 }
 269
 270 /**
 271  * Handles page transfer errors at VM level.
 272  *
 273  * This takes inode as a separate argument, because inode on which error is to
 274  * be set can be different from \a vmpage inode in case of direct-io.
 275  */
 276 static void vvp_vmpage_error(struct inode *inode, cfs_page_t *vmpage, int ioret)
 277 {
 278         if (ioret == 0)
 279                 ClearPageError(vmpage);
 280         else if (ioret != -EINTR) {
 281                 SetPageError(vmpage);
 282                 if (ioret == -ENOSPC)
 283                         set_bit(AS_ENOSPC, &inode->i_mapping->flags);
 284                 else
 285                         set_bit(AS_EIO, &inode->i_mapping->flags);
 286         }
 287 }
 288
 289 static void vvp_page_completion_common(const struct lu_env *env,
 290                                        struct ccc_page *cp, int ioret)
 291 {
 292         struct cl_page    *clp    = cp->cpg_cl.cpl_page;
 293         cfs_page_t        *vmpage = cp->cpg_page;
 294         struct inode      *inode  = ccc_object_inode(clp->cp_obj);
 295
 296         LINVRNT(cl_page_is_vmlocked(env, clp));
 297
 298         if (!clp->cp_sync_io && clp->cp_type == CPT_CACHEABLE) {
 299                 /*
 300                  * Only mark the page error only when it's a cacheable page
 301                  * and NOT a sync io.
 302                  *
 303                  * For sync IO and direct IO(CPT_TRANSIENT), the error is able
 304                  * to be seen by application, so we don't need to mark a page
 305                  * as error at all.
 306                  */
 307                 vvp_vmpage_error(inode, vmpage, ioret);
 308                 unlock_page(vmpage);
 309         }
 310 }
 311
 312 static void vvp_page_completion_read(const struct lu_env *env,
 313                                      const struct cl_page_slice *slice,
 314                                      int ioret)
 315 {
 316         struct ccc_page *cp    = cl2ccc_page(slice);
 317         struct cl_page  *page  = cl_page_top(slice->cpl_page);
 318         struct inode    *inode = ccc_object_inode(page->cp_obj);
 319         ENTRY;
 320
 321         CL_PAGE_HEADER(D_PAGE, env, page, "completing READ with %d\n", ioret);
 322
 323         if (cp->cpg_defer_uptodate)
 324                 ll_ra_count_put(ll_i2sbi(inode), 1);
 325
 326         if (ioret == 0)  {
 327                 /* XXX: do we need this for transient pages? */
 328                 if (!cp->cpg_defer_uptodate)
 329                         cl_page_export(env, page, 1);
 330         } else
 331                 cp->cpg_defer_uptodate = 0;
 332         vvp_page_completion_common(env, cp, ioret);
 333
 334         EXIT;
 335 }
 336
 337 static void vvp_page_completion_write_common(const struct lu_env *env,
 338                                              const struct cl_page_slice *slice,
 339                                              int ioret)
 340 {
 341         struct ccc_page *cp = cl2ccc_page(slice);
 342
 343         /*
 344          * TODO: Actually it makes sense to add the page into oap pending
 345          * list again and so that we don't need to take the page out from
 346          * SoM write pending list, if we just meet a recoverable error,
 347          * -ENOMEM, etc.
 348          * To implement this, we just need to return a non zero value in
 349          * ->cpo_completion method. The underlying transfer should be notified
 350          * and then re-add the page into pending transfer queue.  -jay
 351          */
 352         cp->cpg_write_queued = 0;
 353         vvp_write_complete(cl2ccc(slice->cpl_obj), cp);
 354
 355         vvp_page_completion_common(env, cp, ioret);
 356 }
 357
 358 static void vvp_page_completion_write(const struct lu_env *env,
 359                                       const struct cl_page_slice *slice,
 360                                       int ioret)
 361 {
 362         struct ccc_page *cp     = cl2ccc_page(slice);
 363         struct cl_page  *pg     = slice->cpl_page;
 364         cfs_page_t      *vmpage = cp->cpg_page;
 365
 366         ENTRY;
 367
 368         LINVRNT(cl_page_is_vmlocked(env, pg));
 369         LASSERT(PageWriteback(vmpage));
 370
 371         CL_PAGE_HEADER(D_PAGE, env, pg, "completing WRITE with %d\n", ioret);
 372
 373         vvp_page_completion_write_common(env, slice, ioret);
 374         end_page_writeback(vmpage);
 375         EXIT;
 376 }
 377
 378 /**
 379  * Implements cl_page_operations::cpo_make_ready() method.
 380  *
 381  * This is called to yank a page from the transfer cache and to send it out as
 382  * a part of transfer. This function try-locks the page. If try-lock failed,
 383  * page is owned by some concurrent IO, and should be skipped (this is bad,
 384  * but hopefully rare situation, as it usually results in transfer being
 385  * shorter than possible).
 386  *
 387  * \retval 0      success, page can be placed into transfer
 388  *
 389  * \retval -EAGAIN page is either used by concurrent IO has been
 390  * truncated. Skip it.
 391  */
 392 static int vvp_page_make_ready(const struct lu_env *env,
 393                                const struct cl_page_slice *slice)
 394 {
 395         cfs_page_t *vmpage = cl2vm_page(slice);
 396         struct cl_page *pg = slice->cpl_page;
 397         int result;
 398
 399         result = -EAGAIN;
 400         /* we're trying to write, but the page is locked.. come back later */
 401         if (!TestSetPageLocked(vmpage)) {
 402                 if (pg->cp_state == CPS_CACHED) {
 403                         /*
 404                          * We can cancel IO if page wasn't dirty after all.
 405                          */
 406                         clear_page_dirty_for_io(vmpage);
 407                         /*
 408                          * This actually clears the dirty bit in the radix
 409                          * tree.
 410                          */
 411                         set_page_writeback(vmpage);
 412                         vvp_write_pending(cl2ccc(slice->cpl_obj),
 413                                           cl2ccc_page(slice));
 414                         CL_PAGE_HEADER(D_PAGE, env, pg, "readied\n");
 415                         result = 0;
 416                 } else
 417                         /*
 418                          * Page was concurrently truncated.
 419                          */
 420                         LASSERT(pg->cp_state == CPS_FREEING);
 421         }
 422         RETURN(result);
 423 }
 424
 425 static int vvp_page_print(const struct lu_env *env,
 426                           const struct cl_page_slice *slice,
 427                           void *cookie, lu_printer_t printer)
 428 {
 429         struct ccc_page *vp = cl2ccc_page(slice);
 430         cfs_page_t      *vmpage = vp->cpg_page;
 431
 432         (*printer)(env, cookie, LUSTRE_VVP_NAME"-page@%p(%d:%d:%d) "
 433                    "vm@%p ",
 434                    vp, vp->cpg_defer_uptodate, vp->cpg_ra_used,
 435                    vp->cpg_write_queued, vmpage);
 436         if (vmpage != NULL) {
 437                 (*printer)(env, cookie, "%lx %d:%d %lx %lu %slru",
 438                            (long)vmpage->flags, page_count(vmpage),
 439                            page_mapcount(vmpage), vmpage->private,
 440                            page_index(vmpage),
 441                            list_empty(&vmpage->lru) ? "not-" : "");
 442         }
 443         (*printer)(env, cookie, "\n");
 444         return 0;
 445 }
 446
 447 static const struct cl_page_operations vvp_page_ops = {
 448         .cpo_own           = vvp_page_own,
 449         .cpo_assume        = vvp_page_assume,
 450         .cpo_unassume      = vvp_page_unassume,
 451         .cpo_disown        = vvp_page_disown,
 452         .cpo_vmpage        = ccc_page_vmpage,
 453         .cpo_discard       = vvp_page_discard,
 454         .cpo_delete        = vvp_page_delete,
 455         .cpo_unmap         = vvp_page_unmap,
 456         .cpo_export        = vvp_page_export,
 457         .cpo_is_vmlocked   = vvp_page_is_vmlocked,
 458         .cpo_fini          = vvp_page_fini,
 459         .cpo_print         = vvp_page_print,
 460         .cpo_is_under_lock = ccc_page_is_under_lock,
 461         .io = {
 462                 [CRT_READ] = {
 463                         .cpo_prep        = vvp_page_prep_read,
 464                         .cpo_completion  = vvp_page_completion_read,
 465                         .cpo_make_ready  = ccc_fail,
 466                 },
 467                 [CRT_WRITE] = {
 468                         .cpo_prep        = vvp_page_prep_write,
 469                         .cpo_completion  = vvp_page_completion_write,
 470                         .cpo_make_ready  = vvp_page_make_ready,
 471                 }
 472         }
 473 };
 474
 475 static void vvp_transient_page_verify(const struct cl_page *page)
 476 {
 477         struct inode *inode = ccc_object_inode(page->cp_obj);
 478
 479         LASSERT(!TRYLOCK_INODE_MUTEX(inode));
 480         /* LASSERT_SEM_LOCKED(&inode->i_alloc_sem); */
 481 }
 482
 483 static int vvp_transient_page_own(const struct lu_env *env,
 484                                   const struct cl_page_slice *slice,
 485                                   struct cl_io *unused, int nonblock)
 486 {
 487         vvp_transient_page_verify(slice->cpl_page);
 488         return 0;
 489 }
 490
 491 static void vvp_transient_page_assume(const struct lu_env *env,
 492                                       const struct cl_page_slice *slice,
 493                                       struct cl_io *unused)
 494 {
 495         vvp_transient_page_verify(slice->cpl_page);
 496 }
 497
 498 static void vvp_transient_page_unassume(const struct lu_env *env,
 499                                         const struct cl_page_slice *slice,
 500                                         struct cl_io *unused)
 501 {
 502         vvp_transient_page_verify(slice->cpl_page);
 503 }
 504
 505 static void vvp_transient_page_disown(const struct lu_env *env,
 506                                       const struct cl_page_slice *slice,
 507                                       struct cl_io *unused)
 508 {
 509         vvp_transient_page_verify(slice->cpl_page);
 510 }
 511
 512 static void vvp_transient_page_discard(const struct lu_env *env,
 513                                        const struct cl_page_slice *slice,
 514                                        struct cl_io *unused)
 515 {
 516         struct cl_page *page = slice->cpl_page;
 517
 518         vvp_transient_page_verify(slice->cpl_page);
 519
 520         /*
 521          * For transient pages, remove it from the radix tree.
 522          */
 523         cl_page_delete(env, page);
 524 }
 525
 526 static int vvp_transient_page_is_vmlocked(const struct lu_env *env,
 527                                           const struct cl_page_slice *slice)
 528 {
 529         struct inode    *inode = ccc_object_inode(slice->cpl_obj);
 530         int              locked;
 531
 532         locked = !TRYLOCK_INODE_MUTEX(inode);
 533         if (!locked)
 534                 UNLOCK_INODE_MUTEX(inode);
 535         return locked ? -EBUSY : -ENODATA;
 536 }
 537
 538 static void
 539 vvp_transient_page_completion_write(const struct lu_env *env,
 540                                     const struct cl_page_slice *slice,
 541                                     int ioret)
 542 {
 543         vvp_transient_page_verify(slice->cpl_page);
 544         vvp_page_completion_write_common(env, slice, ioret);
 545 }
 546
 547
 548 static void vvp_transient_page_fini(const struct lu_env *env,
 549                                     struct cl_page_slice *slice)
 550 {
 551         struct ccc_page *cp = cl2ccc_page(slice);
 552         struct cl_page *clp = slice->cpl_page;
 553         struct ccc_object *clobj = cl2ccc(clp->cp_obj);
 554
 555         vvp_page_fini_common(cp);
 556         LASSERT(!TRYLOCK_INODE_MUTEX(clobj->cob_inode));
 557         clobj->cob_transient_pages--;
 558 }
 559
 560 static const struct cl_page_operations vvp_transient_page_ops = {
 561         .cpo_own           = vvp_transient_page_own,
 562         .cpo_assume        = vvp_transient_page_assume,
 563         .cpo_unassume      = vvp_transient_page_unassume,
 564         .cpo_disown        = vvp_transient_page_disown,
 565         .cpo_discard       = vvp_transient_page_discard,
 566         .cpo_vmpage        = ccc_page_vmpage,
 567         .cpo_fini          = vvp_transient_page_fini,
 568         .cpo_is_vmlocked   = vvp_transient_page_is_vmlocked,
 569         .cpo_print         = vvp_page_print,
 570         .cpo_is_under_lock = ccc_page_is_under_lock,
 571         .io = {
 572                 [CRT_READ] = {
 573                         .cpo_prep        = ccc_transient_page_prep,
 574                         .cpo_completion  = vvp_page_completion_read,
 575                 },
 576                 [CRT_WRITE] = {
 577                         .cpo_prep        = ccc_transient_page_prep,
 578                         .cpo_completion  = vvp_transient_page_completion_write,
 579                 }
 580         }
 581 };
 582
 583 struct cl_page *vvp_page_init(const struct lu_env *env, struct cl_object *obj,
 584                               struct cl_page *page, cfs_page_t *vmpage)
 585 {
 586         struct ccc_page *cpg;
 587         int result;
 588
 589         CLOBINVRNT(env, obj, ccc_object_invariant(obj));
 590
 591         OBD_SLAB_ALLOC_PTR_GFP(cpg, vvp_page_kmem, CFS_ALLOC_IO);
 592         if (cpg != NULL) {
 593                 cpg->cpg_page = vmpage;
 594                 page_cache_get(vmpage);
 595
 596                 CFS_INIT_LIST_HEAD(&cpg->cpg_pending_linkage);
 597                 if (page->cp_type == CPT_CACHEABLE) {
 598                         SetPagePrivate(vmpage);
 599                         vmpage->private = (unsigned long)page;
 600                         cl_page_slice_add(page, &cpg->cpg_cl, obj,
 601                                           &vvp_page_ops);
 602                 } else {
 603                         struct ccc_object *clobj = cl2ccc(obj);
 604
 605                         LASSERT(!TRYLOCK_INODE_MUTEX(clobj->cob_inode));
 606                         cl_page_slice_add(page, &cpg->cpg_cl, obj,
 607                                           &vvp_transient_page_ops);
 608                         clobj->cob_transient_pages++;
 609                 }
 610                 result = 0;
 611         } else
 612                 result = -ENOMEM;
 613         return ERR_PTR(result);
 614 }
 615