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