lustre/obdfilter/filter_io.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  * lustre/obdfilter/filter_io.c
  37  *
  38  * Author: Peter Braam <braam@clusterfs.com>
  39  * Author: Andreas Dilger <adilger@clusterfs.com>
  40  * Author: Phil Schwan <phil@clusterfs.com>
  41  */
  42
  43 #define DEBUG_SUBSYSTEM S_FILTER
  44
  45 #ifndef AUTOCONF_INCLUDED
  46 #include <linux/config.h>
  47 #endif
  48 #include <linux/module.h>
  49 #include <linux/pagemap.h> // XXX kill me soon
  50 #include <linux/version.h>
  51
  52 #include <obd_class.h>
  53 #include <obd_ost.h>
  54 #include <lustre_fsfilt.h>
  55 #include "filter_internal.h"
  56
  57 int *obdfilter_created_scratchpad;
  58
  59 /* Grab the dirty and seen grant announcements from the incoming obdo.
  60  * We will later calculate the clients new grant and return it.
  61  * Caller must hold osfs lock */
  62 void filter_grant_incoming(struct obd_export *exp, struct obdo *oa)
  63 {
  64         struct filter_export_data *fed;
  65         struct obd_device *obd = exp->exp_obd;
  66         ENTRY;
  67
  68         LASSERT_SPIN_LOCKED(&obd->obd_osfs_lock);
  69
  70         if ((oa->o_valid & (OBD_MD_FLBLOCKS|OBD_MD_FLGRANT)) !=
  71                                         (OBD_MD_FLBLOCKS|OBD_MD_FLGRANT)) {
  72                 oa->o_valid &= ~OBD_MD_FLGRANT;
  73                 EXIT;
  74                 return;
  75         }
  76
  77         fed = &exp->exp_filter_data;
  78
  79         /* Add some margin, since there is a small race if other RPCs arrive
  80          * out-or-order and have already consumed some grant.  We want to
  81          * leave this here in case there is a large error in accounting. */
  82         CDEBUG(D_CACHE,
  83                "%s: cli %s/%p reports grant: "LPU64" dropped: %u, local: %lu\n",
  84                obd->obd_name, exp->exp_client_uuid.uuid, exp, oa->o_grant,
  85                oa->o_dropped, fed->fed_grant);
  86
  87         /* Update our accounting now so that statfs takes it into account.
  88          * Note that fed_dirty is only approximate and can become incorrect
  89          * if RPCs arrive out-of-order.  No important calculations depend
  90          * on fed_dirty however, but we must check sanity to not assert. */
  91         if ((long long)oa->o_dirty < 0)
  92                 oa->o_dirty = 0;
  93         else if (oa->o_dirty > fed->fed_grant + 4 * FILTER_GRANT_CHUNK)
  94                 oa->o_dirty = fed->fed_grant + 4 * FILTER_GRANT_CHUNK;
  95         obd->u.filter.fo_tot_dirty += oa->o_dirty - fed->fed_dirty;
  96         if (fed->fed_grant < oa->o_dropped) {
  97                 CDEBUG(D_CACHE,"%s: cli %s/%p reports %u dropped > grant %lu\n",
  98                        obd->obd_name, exp->exp_client_uuid.uuid, exp,
  99                        oa->o_dropped, fed->fed_grant);
 100                 oa->o_dropped = 0;
 101         }
 102         if (obd->u.filter.fo_tot_granted < oa->o_dropped) {
 103                 CERROR("%s: cli %s/%p reports %u dropped > tot_grant "LPU64"\n",
 104                        obd->obd_name, exp->exp_client_uuid.uuid, exp,
 105                        oa->o_dropped, obd->u.filter.fo_tot_granted);
 106                 oa->o_dropped = 0;
 107         }
 108         obd->u.filter.fo_tot_granted -= oa->o_dropped;
 109         fed->fed_grant -= oa->o_dropped;
 110         fed->fed_dirty = oa->o_dirty;
 111
 112         if (oa->o_flags & OBD_FL_SHRINK_GRANT) {
 113                 obd_size left_space = filter_grant_space_left(exp);
 114                 struct filter_obd *filter = &exp->exp_obd->u.filter;
 115
 116                 /*Only if left_space < fo_tot_clients * 32M,
 117                  *then the grant space could be shrinked */
 118                 if (left_space < filter->fo_tot_granted_clients *
 119                                  FILTER_GRANT_SHRINK_LIMIT) {
 120                         fed->fed_grant -= oa->o_grant;
 121                         filter->fo_tot_granted -= oa->o_grant;
 122                         CDEBUG(D_CACHE, "%s: cli %s/%p shrink "LPU64
 123                                "fed_grant %ld total "LPU64"\n",
 124                                obd->obd_name, exp->exp_client_uuid.uuid,
 125                                exp, oa->o_grant, fed->fed_grant,
 126                                filter->fo_tot_granted);
 127                         oa->o_grant = 0;
 128                 }
 129         }
 130
 131         if (fed->fed_dirty < 0 || fed->fed_grant < 0 || fed->fed_pending < 0) {
 132                 CERROR("%s: cli %s/%p dirty %ld pend %ld grant %ld\n",
 133                        obd->obd_name, exp->exp_client_uuid.uuid, exp,
 134                        fed->fed_dirty, fed->fed_pending, fed->fed_grant);
 135                 spin_unlock(&obd->obd_osfs_lock);
 136                 LBUG();
 137         }
 138         EXIT;
 139 }
 140
 141 /* Figure out how much space is available between what we've granted
 142  * and what remains in the filesystem.  Compensate for ext3 indirect
 143  * block overhead when computing how much free space is left ungranted.
 144  *
 145  * Caller must hold obd_osfs_lock. */
 146 obd_size filter_grant_space_left(struct obd_export *exp)
 147 {
 148         struct obd_device *obd = exp->exp_obd;
 149         int blockbits = obd->u.obt.obt_sb->s_blocksize_bits;
 150         obd_size tot_granted = obd->u.filter.fo_tot_granted, avail, left = 0;
 151         int rc, statfs_done = 0;
 152
 153         LASSERT_SPIN_LOCKED(&obd->obd_osfs_lock);
 154
 155         if (cfs_time_before_64(obd->obd_osfs_age, cfs_time_current_64() - HZ)) {
 156 restat:
 157                 rc = fsfilt_statfs(obd, obd->u.obt.obt_sb,
 158                                    cfs_time_current_64() + HZ);
 159                 if (rc) /* N.B. statfs can't really fail */
 160                         RETURN(0);
 161                 statfs_done = 1;
 162         }
 163
 164         avail = obd->obd_osfs.os_bavail;
 165         left = avail - (avail >> (blockbits - 3)); /* (d)indirect */
 166         if (left > GRANT_FOR_LLOG(obd)) {
 167                 left = (left - GRANT_FOR_LLOG(obd)) << blockbits;
 168         } else {
 169                 left = 0 /* << blockbits */;
 170         }
 171
 172         if (!statfs_done && left < 32 * FILTER_GRANT_CHUNK + tot_granted) {
 173                 CDEBUG(D_CACHE, "fs has no space left and statfs too old\n");
 174                 goto restat;
 175         }
 176
 177         if (left >= tot_granted) {
 178                 left -= tot_granted;
 179         } else {
 180                 if (left < tot_granted - obd->u.filter.fo_tot_pending) {
 181                         CERROR("%s: cli %s/%p grant "LPU64" > available "
 182                                LPU64" and pending "LPU64"\n", obd->obd_name,
 183                                exp->exp_client_uuid.uuid, exp, tot_granted,
 184                                left, obd->u.filter.fo_tot_pending);
 185                 }
 186                 left = 0;
 187         }
 188
 189         CDEBUG(D_CACHE, "%s: cli %s/%p free: "LPU64" avail: "LPU64" grant "LPU64
 190                " left: "LPU64" pending: "LPU64"\n", obd->obd_name,
 191                exp->exp_client_uuid.uuid, exp,
 192                obd->obd_osfs.os_bfree << blockbits, avail << blockbits,
 193                tot_granted, left, obd->u.filter.fo_tot_pending);
 194
 195         return left;
 196 }
 197
 198 /* Calculate how much grant space to allocate to this client, based on how
 199  * much space is currently free and how much of that is already granted.
 200  *
 201  * Caller must hold obd_osfs_lock. */
 202 long filter_grant(struct obd_export *exp, obd_size current_grant,
 203                   obd_size want, obd_size fs_space_left)
 204 {
 205         struct obd_device *obd = exp->exp_obd;
 206         struct filter_export_data *fed = &exp->exp_filter_data;
 207         int blockbits = obd->u.obt.obt_sb->s_blocksize_bits;
 208         __u64 grant = 0;
 209
 210         LASSERT_SPIN_LOCKED(&obd->obd_osfs_lock);
 211
 212         /* Grant some fraction of the client's requested grant space so that
 213          * they are not always waiting for write credits (not all of it to
 214          * avoid overgranting in face of multiple RPCs in flight).  This
 215          * essentially will be able to control the OSC_MAX_RIF for a client.
 216          *
 217          * If we do have a large disparity between what the client thinks it
 218          * has and what we think it has, don't grant very much and let the
 219          * client consume its grant first.  Either it just has lots of RPCs
 220          * in flight, or it was evicted and its grants will soon be used up. */
 221         if (want > 0x7fffffff) {
 222                 CERROR("%s: client %s/%p requesting > 2GB grant "LPU64"\n",
 223                        obd->obd_name, exp->exp_client_uuid.uuid, exp, want);
 224         } else if (current_grant < want &&
 225                    current_grant < fed->fed_grant + FILTER_GRANT_CHUNK) {
 226                 grant = min((want >> blockbits),
 227                             (fs_space_left >> blockbits) / 8);
 228                 grant <<= blockbits;
 229
 230                 if (grant) {
 231                         /* Allow >FILTER_GRANT_CHUNK size when clients
 232                          * reconnect due to a server reboot.
 233                          */
 234                         if ((grant > FILTER_GRANT_CHUNK) &&
 235                             (!obd->obd_recovering))
 236                                 grant = FILTER_GRANT_CHUNK;
 237
 238                         obd->u.filter.fo_tot_granted += grant;
 239                         fed->fed_grant += grant;
 240                         if (fed->fed_grant < 0) {
 241                                 CERROR("%s: cli %s/%p grant %ld want "LPU64
 242                                        "current"LPU64"\n",
 243                                        obd->obd_name, exp->exp_client_uuid.uuid,
 244                                        exp, fed->fed_grant, want,current_grant);
 245                                 spin_unlock(&obd->obd_osfs_lock);
 246                                 LBUG();
 247                         }
 248                 }
 249         }
 250
 251         CDEBUG(D_CACHE,
 252                "%s: cli %s/%p wants: "LPU64" current grant "LPU64
 253                " granting: "LPU64"\n", obd->obd_name, exp->exp_client_uuid.uuid,
 254                exp, want, current_grant, grant);
 255         CDEBUG(D_CACHE,
 256                "%s: cli %s/%p tot cached:"LPU64" granted:"LPU64
 257                " num_exports: %d\n", obd->obd_name, exp->exp_client_uuid.uuid,
 258                exp, obd->u.filter.fo_tot_dirty,
 259                obd->u.filter.fo_tot_granted, obd->obd_num_exports);
 260
 261         return grant;
 262 }
 263
 264 /*
 265  * the routine is used to request pages from pagecache
 266  *
 267  * use GFP_NOFS for requests from a local client not allowing to enter FS
 268  * as we might end up waiting on a page he sent in the request we're serving.
 269  * use __GFP_HIGHMEM so that the pages can use all of the available memory
 270  * on 32-bit machines
 271  * use more agressive GFP_HIGHUSER flags from non-local clients to be able to
 272  * generate more memory pressure, but at the same time use __GFP_NOMEMALLOC
 273  * in order not to exhaust emergency reserves.
 274  *
 275  * See Bug 19529 and Bug 19917 for details.
 276  */
 277 static struct page *filter_get_page(struct obd_device *obd,
 278                                     struct inode *inode,
 279                                     obd_off offset,
 280                                     int localreq)
 281 {
 282         struct page *page;
 283
 284         page = find_or_create_page(inode->i_mapping, offset >> CFS_PAGE_SHIFT,
 285                                    (localreq ? (GFP_NOFS | __GFP_HIGHMEM)
 286                                              : (GFP_HIGHUSER | __GFP_NOMEMALLOC)));
 287         if (unlikely(page == NULL))
 288                 lprocfs_counter_add(obd->obd_stats, LPROC_FILTER_NO_PAGE, 1);
 289
 290         return page;
 291 }
 292
 293 /*
 294  * the routine initializes array of local_niobuf from remote_niobuf
 295  */
 296 static int filter_map_remote_to_local(int objcount, struct obd_ioobj *obj,
 297                                       struct niobuf_remote *nb,
 298                                       int *nrpages, struct niobuf_local *res)
 299 {
 300         struct niobuf_remote *rnb;
 301         struct niobuf_local *lnb;
 302         int i, max;
 303         ENTRY;
 304
 305         /* we don't support multiobject RPC yet
 306          * ost_brw_read() and ost_brw_write() check this */
 307         LASSERT(objcount == 1);
 308
 309         max = *nrpages;
 310         *nrpages = 0;
 311         for (i = 0, rnb = nb, lnb = res; i < obj->ioo_bufcnt; i++, rnb++) {
 312                 obd_off offset = rnb->offset;
 313                 unsigned int len = rnb->len;
 314
 315                 while (len > 0) {
 316                         int poff = offset & (CFS_PAGE_SIZE - 1);
 317                         int plen = CFS_PAGE_SIZE - poff;
 318
 319                         if (*nrpages >= max) {
 320                                 CERROR("small array of local bufs: %d\n", max);
 321                                 RETURN(-EINVAL);
 322                         }
 323
 324                         if (plen > len)
 325                                 plen = len;
 326                         lnb->offset = offset;
 327                         lnb->len = plen;
 328                         lnb->flags = rnb->flags;
 329                         lnb->page = NULL;
 330                         lnb->rc = 0;
 331                         lnb->lnb_grant_used = 0;
 332
 333                         LASSERTF(plen <= len, "plen %u, len %u\n", plen, len);
 334                         offset += plen;
 335                         len -= plen;
 336                         lnb++;
 337                         (*nrpages)++;
 338                 }
 339         }
 340         RETURN(0);
 341 }
 342
 343 /*
 344  * the function is used to free all pages used for request
 345  * just to mimic cacheless OSS which don't occupy much memory
 346  */
 347 void filter_invalidate_cache(struct obd_device *obd, struct obd_ioobj *obj,
 348                              struct niobuf_remote *nb, struct inode *inode)
 349 {
 350         struct niobuf_remote *rnb;
 351         int i;
 352
 353         LASSERT(inode != NULL);
 354
 355         for (i = 0, rnb = nb; i < obj->ioo_bufcnt; i++, rnb++) {
 356                 obd_off start;
 357                 obd_off end;
 358
 359                 start = rnb->offset >> CFS_PAGE_SHIFT;
 360                 end = (rnb->offset + rnb->len) >> CFS_PAGE_SHIFT;
 361                 invalidate_mapping_pages(inode->i_mapping, start, end);
 362                 /* just to avoid warnings */
 363                 start = 0;
 364                 end = 0;
 365         }
 366 }
 367
 368 /*
 369  * the invalidate above doesn't work during read because lnet pins pages.
 370  * The truncate is used here instead to drop pages from cache
 371  */
 372 void filter_truncate_cache(struct obd_device *obd, struct obd_ioobj *obj,
 373                            struct niobuf_remote *nb, int pages,
 374                            struct niobuf_local *res, struct inode *inode)
 375 {
 376         struct niobuf_remote *rnb;
 377         int i;
 378
 379         LASSERT(inode != NULL);
 380 #ifdef HAVE_TRUNCATE_RANGE
 381         for (i = 0, rnb = nb; i < obj->ioo_bufcnt; i++, rnb++) {
 382                 /* remove pages in which range is fit */
 383                 truncate_inode_pages_range(inode->i_mapping,
 384                                            rnb->offset & CFS_PAGE_MASK,
 385                                            (rnb->offset + rnb->len - 1) |
 386                                            ~CFS_PAGE_MASK);
 387         }
 388 #elif (defined HAVE_TRUNCATE_COMPLETE)
 389         for (i = 0, lnb = res; i < pages; i++, lnb++)
 390                 truncate_complete_page(inode->i_mapping, lnb->page);
 391 #else
 392 #error "Nor truncate_inode_pages_range or truncate_complete_page are supported"
 393 #endif
 394 }
 395
 396 static int filter_preprw_read(int cmd, struct obd_export *exp, struct obdo *oa,
 397                               int objcount, struct obd_ioobj *obj,
 398                               struct niobuf_remote *nb,
 399                               int *npages, struct niobuf_local *res,
 400                               struct obd_trans_info *oti,
 401                               struct lustre_capa *capa)
 402 {
 403         struct obd_device *obd = exp->exp_obd;
 404         struct timeval start, end;
 405         struct lvfs_run_ctxt saved;
 406         struct niobuf_local *lnb;
 407         struct dentry *dentry = NULL;
 408         struct inode *inode = NULL;
 409         void *iobuf = NULL;
 410         int rc = 0, i, tot_bytes = 0;
 411         unsigned long now = jiffies;
 412         long timediff;
 413         ENTRY;
 414
 415         /* We are currently not supporting multi-obj BRW_READ RPCS at all.
 416          * When we do this function's dentry cleanup will need to be fixed.
 417          * These values are verified in ost_brw_write() from the wire. */
 418         LASSERTF(objcount == 1, "%d\n", objcount);
 419         LASSERTF(obj->ioo_bufcnt > 0, "%d\n", obj->ioo_bufcnt);
 420
 421         rc = filter_auth_capa(exp, NULL, obdo_mdsno(oa), capa,
 422                               CAPA_OPC_OSS_READ);
 423         if (rc)
 424                 RETURN(rc);
 425
 426         if (oa && oa->o_valid & OBD_MD_FLGRANT) {
 427                 spin_lock(&obd->obd_osfs_lock);
 428                 filter_grant_incoming(exp, oa);
 429
 430                 if (!(oa->o_flags & OBD_FL_SHRINK_GRANT))
 431                         oa->o_grant = 0;
 432                 spin_unlock(&obd->obd_osfs_lock);
 433         }
 434
 435         iobuf = filter_iobuf_get(&obd->u.filter, oti);
 436         if (IS_ERR(iobuf))
 437                 RETURN(PTR_ERR(iobuf));
 438
 439         push_ctxt(&saved, &obd->obd_lvfs_ctxt, NULL);
 440         dentry = filter_oa2dentry(obd, oa);
 441         if (IS_ERR(dentry)) {
 442                 rc = PTR_ERR(dentry);
 443                 dentry = NULL;
 444                 GOTO(cleanup, rc);
 445         }
 446
 447         inode = dentry->d_inode;
 448
 449         obdo_to_inode(inode, oa, OBD_MD_FLATIME);
 450
 451         rc = filter_map_remote_to_local(objcount, obj, nb, npages, res);
 452         if (rc)
 453                 GOTO(cleanup, rc);
 454
 455         fsfilt_check_slow(obd, now, "preprw_read setup");
 456
 457         /* find pages for all segments, fill array with them */
 458         do_gettimeofday(&start);
 459         for (i = 0, lnb = res; i < *npages; i++, lnb++) {
 460
 461                 lnb->dentry = dentry;
 462
 463                 if (i_size_read(inode) <= lnb->offset)
 464                         /* If there's no more data, abort early.  lnb->rc == 0,
 465                          * so it's easy to detect later. */
 466                         break;
 467
 468                 lnb->page = filter_get_page(obd, inode, lnb->offset, 0);
 469                 if (lnb->page == NULL)
 470                         GOTO(cleanup, rc = -ENOMEM);
 471
 472                 lprocfs_counter_add(obd->obd_stats, LPROC_FILTER_CACHE_ACCESS, 1);
 473
 474                 if (i_size_read(inode) < lnb->offset + lnb->len - 1)
 475                         lnb->rc = i_size_read(inode) - lnb->offset;
 476                 else
 477                         lnb->rc = lnb->len;
 478
 479                 tot_bytes += lnb->rc;
 480
 481                 if (PageUptodate(lnb->page)) {
 482                         lprocfs_counter_add(obd->obd_stats,
 483                                             LPROC_FILTER_CACHE_HIT, 1);
 484                         continue;
 485                 }
 486
 487                 lprocfs_counter_add(obd->obd_stats, LPROC_FILTER_CACHE_MISS, 1);
 488                 filter_iobuf_add_page(obd, iobuf, inode, lnb->page);
 489         }
 490         do_gettimeofday(&end);
 491         timediff = cfs_timeval_sub(&end, &start, NULL);
 492         lprocfs_counter_add(obd->obd_stats, LPROC_FILTER_GET_PAGE, timediff);
 493
 494         if (OBD_FAIL_CHECK(OBD_FAIL_OST_NOMEM))
 495                 GOTO(cleanup, rc = -ENOMEM);
 496
 497         fsfilt_check_slow(obd, now, "start_page_read");
 498
 499         rc = filter_direct_io(OBD_BRW_READ, dentry, iobuf,
 500                               exp, NULL, NULL, NULL);
 501         if (rc)
 502                 GOTO(cleanup, rc);
 503
 504         lprocfs_counter_add(obd->obd_stats, LPROC_FILTER_READ_BYTES, tot_bytes);
 505
 506         if (exp->exp_nid_stats && exp->exp_nid_stats->nid_stats)
 507                 lprocfs_counter_add(exp->exp_nid_stats->nid_stats,
 508                                     LPROC_FILTER_READ_BYTES, tot_bytes);
 509
 510         EXIT;
 511
 512  cleanup:
 513         /* unlock pages to allow access from concurrent OST_READ */
 514         for (i = 0, lnb = res; i < *npages; i++, lnb++) {
 515                 if (lnb->page) {
 516                         LASSERT(PageLocked(lnb->page));
 517                         unlock_page(lnb->page);
 518
 519                         if (rc) {
 520                                 page_cache_release(lnb->page);
 521                                 lnb->page = NULL;
 522                         }
 523                 }
 524         }
 525
 526         if (rc != 0) {
 527                 if (dentry != NULL)
 528                         f_dput(dentry);
 529         }
 530
 531         filter_iobuf_put(&obd->u.filter, iobuf, oti);
 532
 533         pop_ctxt(&saved, &obd->obd_lvfs_ctxt, NULL);
 534         if (rc)
 535                 CERROR("io error %d\n", rc);
 536
 537         return rc;
 538 }
 539
 540 /* When clients have dirtied as much space as they've been granted they
 541  * fall through to sync writes.  These sync writes haven't been expressed
 542  * in grants and need to error with ENOSPC when there isn't room in the
 543  * filesystem for them after grants are taken into account.  However,
 544  * writeback of the dirty data that was already granted space can write
 545  * right on through.
 546  *
 547  * Caller must hold obd_osfs_lock. */
 548 static int filter_grant_check(struct obd_export *exp, struct obdo *oa,
 549                               int objcount, struct fsfilt_objinfo *fso,
 550                               int niocount, struct niobuf_local *lnb,
 551                               obd_size *left, struct inode *inode)
 552 {
 553         struct filter_export_data *fed = &exp->exp_filter_data;
 554         int blocksize = exp->exp_obd->u.obt.obt_sb->s_blocksize;
 555         unsigned long used = 0, ungranted = 0, using;
 556         int i, rc = -ENOSPC, obj, n = 0;
 557
 558         LASSERT_SPIN_LOCKED(&exp->exp_obd->obd_osfs_lock);
 559
 560         for (obj = 0; obj < objcount; obj++) {
 561                 for (i = 0; i < fso[obj].fso_bufcnt; i++, n++) {
 562                         int tmp, bytes;
 563
 564                         /* should match the code in osc_exit_cache */
 565                         bytes = lnb[n].len;
 566                         bytes += lnb[n].offset & (blocksize - 1);
 567                         tmp = (lnb[n].offset + lnb[n].len) & (blocksize - 1);
 568                         if (tmp)
 569                                 bytes += blocksize - tmp;
 570
 571                         if ((lnb[n].flags & OBD_BRW_FROM_GRANT) &&
 572                             (oa->o_valid & OBD_MD_FLGRANT)) {
 573                                 if (fed->fed_grant < used + bytes) {
 574                                         CDEBUG(D_CACHE,
 575                                                "%s: cli %s/%p claims %ld+%d "
 576                                                "GRANT, real grant %lu idx %d\n",
 577                                                exp->exp_obd->obd_name,
 578                                                exp->exp_client_uuid.uuid, exp,
 579                                                used, bytes, fed->fed_grant, n);
 580                                 } else {
 581                                         used += bytes;
 582                                         lnb[n].flags |= OBD_BRW_GRANTED;
 583                                         lnb[n].lnb_grant_used = bytes;
 584                                         CDEBUG(0, "idx %d used=%lu\n", n, used);
 585                                         rc = 0;
 586                                         continue;
 587                                 }
 588                         }
 589                         if (*left > ungranted + bytes) {
 590                                 /* if enough space, pretend it was granted */
 591                                 ungranted += bytes;
 592                                 lnb[n].flags |= OBD_BRW_GRANTED;
 593                                 lnb[n].lnb_grant_used = bytes;
 594                                 CDEBUG(0, "idx %d ungranted=%lu\n",n,ungranted);
 595                                 rc = 0;
 596                                 continue;
 597                         }
 598
 599                         /* We can't check for already-mapped blocks here, as
 600                          * it requires dropping the osfs lock to do the bmap.
 601                          * Instead, we return ENOSPC and in that case we need
 602                          * to go through and verify if all of the blocks not
 603                          * marked BRW_GRANTED are already mapped and we can
 604                          * ignore this error. */
 605                         lnb[n].rc = -ENOSPC;
 606                         lnb[n].flags &= ~OBD_BRW_GRANTED;
 607                         CDEBUG(D_CACHE,"%s: cli %s/%p idx %d no space for %d\n",
 608                                exp->exp_obd->obd_name,
 609                                exp->exp_client_uuid.uuid, exp, n, bytes);
 610                 }
 611         }
 612
 613         /* Now substract what client have used already.  We don't subtract
 614          * this from the tot_granted yet, so that other client's can't grab
 615          * that space before we have actually allocated our blocks.  That
 616          * happens in filter_grant_commit() after the writes are done. */
 617         *left -= ungranted;
 618         fed->fed_grant -= used;
 619         fed->fed_pending += used + ungranted;
 620         exp->exp_obd->u.filter.fo_tot_granted += ungranted;
 621         exp->exp_obd->u.filter.fo_tot_pending += used + ungranted;
 622
 623         CDEBUG(D_CACHE,
 624                "%s: cli %s/%p used: %lu ungranted: %lu grant: %lu dirty: %lu\n",
 625                exp->exp_obd->obd_name, exp->exp_client_uuid.uuid, exp, used,
 626                ungranted, fed->fed_grant, fed->fed_dirty);
 627
 628         /* Rough calc in case we don't refresh cached statfs data */
 629         using = (used + ungranted + 1 ) >>
 630                 exp->exp_obd->u.obt.obt_sb->s_blocksize_bits;
 631         if (exp->exp_obd->obd_osfs.os_bavail > using)
 632                 exp->exp_obd->obd_osfs.os_bavail -= using;
 633         else
 634                 exp->exp_obd->obd_osfs.os_bavail = 0;
 635
 636         if (fed->fed_dirty < used) {
 637                 CERROR("%s: cli %s/%p claims used %lu > fed_dirty %lu\n",
 638                        exp->exp_obd->obd_name, exp->exp_client_uuid.uuid, exp,
 639                        used, fed->fed_dirty);
 640                 used = fed->fed_dirty;
 641         }
 642         exp->exp_obd->u.filter.fo_tot_dirty -= used;
 643         fed->fed_dirty -= used;
 644
 645         if (fed->fed_dirty < 0 || fed->fed_grant < 0 || fed->fed_pending < 0) {
 646                 CERROR("%s: cli %s/%p dirty %ld pend %ld grant %ld\n",
 647                        exp->exp_obd->obd_name, exp->exp_client_uuid.uuid, exp,
 648                        fed->fed_dirty, fed->fed_pending, fed->fed_grant);
 649                 spin_unlock(&exp->exp_obd->obd_osfs_lock);
 650                 LBUG();
 651         }
 652         return rc;
 653 }
 654
 655 /* If we ever start to support multi-object BRW RPCs, we will need to get locks
 656  * on mulitple inodes.  That isn't all, because there still exists the
 657  * possibility of a truncate starting a new transaction while holding the ext3
 658  * rwsem = write while some writes (which have started their transactions here)
 659  * blocking on the ext3 rwsem = read => lock inversion.
 660  *
 661  * The handling gets very ugly when dealing with locked pages.  It may be easier
 662  * to just get rid of the locked page code (which has problems of its own) and
 663  * either discover we do not need it anymore (i.e. it was a symptom of another
 664  * bug) or ensure we get the page locks in an appropriate order. */
 665 static int filter_preprw_write(int cmd, struct obd_export *exp, struct obdo *oa,
 666                                int objcount, struct obd_ioobj *obj,
 667                                struct niobuf_remote *nb, int *npages,
 668                                struct niobuf_local *res,
 669                                struct obd_trans_info *oti,
 670                                struct lustre_capa *capa)
 671 {
 672         struct obd_device *obd = exp->exp_obd;
 673         struct timeval start, end;
 674         struct lvfs_run_ctxt saved;
 675         struct niobuf_local *lnb = res;
 676         struct fsfilt_objinfo fso;
 677         struct filter_mod_data *fmd;
 678         struct dentry *dentry = NULL;
 679         void *iobuf;
 680         obd_size left;
 681         unsigned long now = jiffies, timediff;
 682         int rc = 0, i, tot_bytes = 0, cleanup_phase = 0, localreq = 0;
 683         ENTRY;
 684         LASSERT(objcount == 1);
 685         LASSERT(obj->ioo_bufcnt > 0);
 686
 687         rc = filter_auth_capa(exp, NULL, obdo_mdsno(oa), capa,
 688                               CAPA_OPC_OSS_WRITE);
 689         if (rc)
 690                 RETURN(rc);
 691
 692         if (exp->exp_connection->c_peer.nid == exp->exp_connection->c_self)
 693                 localreq = 1;
 694
 695         push_ctxt(&saved, &obd->obd_lvfs_ctxt, NULL);
 696         iobuf = filter_iobuf_get(&obd->u.filter, oti);
 697         if (IS_ERR(iobuf))
 698                 GOTO(cleanup, rc = PTR_ERR(iobuf));
 699         cleanup_phase = 1;
 700
 701         dentry = filter_fid2dentry(obd, NULL, obj->ioo_gr,
 702                                    obj->ioo_id);
 703         if (IS_ERR(dentry))
 704                 GOTO(cleanup, rc = PTR_ERR(dentry));
 705         cleanup_phase = 2;
 706
 707         if (dentry->d_inode == NULL) {
 708                 CERROR("%s: trying to BRW to non-existent file "LPU64"\n",
 709                        obd->obd_name, obj->ioo_id);
 710                 GOTO(cleanup, rc = -ENOENT);
 711         }
 712
 713         if (oa->o_valid & (OBD_MD_FLUID | OBD_MD_FLGID) &&
 714             dentry->d_inode->i_mode & (S_ISUID | S_ISGID)) {
 715                 rc = filter_capa_fixoa(exp, oa, obdo_mdsno(oa), capa);
 716                 if (rc)
 717                         GOTO(cleanup, rc);
 718         }
 719
 720         rc = filter_map_remote_to_local(objcount, obj, nb, npages, res);
 721         if (rc)
 722                 GOTO(cleanup, rc);
 723
 724         fsfilt_check_slow(obd, now, "preprw_write setup");
 725
 726         /* Don't update inode timestamps if this write is older than a
 727          * setattr which modifies the timestamps. b=10150 */
 728         /* XXX when we start having persistent reservations this needs to
 729          * be changed to filter_fmd_get() to create the fmd if it doesn't
 730          * already exist so we can store the reservation handle there. */
 731         fmd = filter_fmd_find(exp, obj->ioo_id, obj->ioo_gr);
 732
 733         LASSERT(oa != NULL);
 734         spin_lock(&obd->obd_osfs_lock);
 735         filter_grant_incoming(exp, oa);
 736         if (fmd && fmd->fmd_mactime_xid > oti->oti_xid)
 737                 oa->o_valid &= ~(OBD_MD_FLMTIME | OBD_MD_FLCTIME |
 738                                  OBD_MD_FLATIME);
 739         else
 740                 obdo_to_inode(dentry->d_inode, oa, OBD_MD_FLATIME |
 741                               OBD_MD_FLMTIME | OBD_MD_FLCTIME);
 742         cleanup_phase = 3;
 743
 744         left = filter_grant_space_left(exp);
 745
 746         fso.fso_dentry = dentry;
 747         fso.fso_bufcnt = *npages;
 748
 749         rc = filter_grant_check(exp, oa, objcount, &fso, *npages, res,
 750                                 &left, dentry->d_inode);
 751
 752         /* do not zero out oa->o_valid as it is used in filter_commitrw_write()
 753          * for setting UID/GID and fid EA in first write time. */
 754         if (oa->o_valid & OBD_MD_FLGRANT)
 755                 oa->o_grant = filter_grant(exp,oa->o_grant,oa->o_undirty,left);
 756
 757         spin_unlock(&obd->obd_osfs_lock);
 758         filter_fmd_put(exp, fmd);
 759
 760         if (rc)
 761                 GOTO(cleanup, rc);
 762         cleanup_phase = 4;
 763
 764         /* Filter truncate first locks i_mutex then partally truncated
 765          * page, filter write code first locks pages then take
 766          * i_mutex.  To avoid a deadlock in case of concurrent
 767          * punch/write requests from one client, filter writes and
 768          * filter truncates are serialized by i_alloc_sem, allowing
 769          * multiple writes or single truncate. */
 770         down_read(&dentry->d_inode->i_alloc_sem);
 771
 772         do_gettimeofday(&start);
 773         for (i = 0, lnb = res; i < *npages; i++, lnb++) {
 774
 775                 /* We still set up for ungranted pages so that granted pages
 776                  * can be written to disk as they were promised, and portals
 777                  * needs to keep the pages all aligned properly. */
 778                 lnb->dentry = dentry;
 779
 780                 lnb->page = filter_get_page(obd, dentry->d_inode, lnb->offset,
 781                                             localreq);
 782                 if (lnb->page == NULL)
 783                         GOTO(cleanup, rc = -ENOMEM);
 784
 785                 /* DLM locking protects us from write and truncate competing
 786                  * for same region, but truncate can leave dirty page in the
 787                  * cache. it's possible the writeout on a such a page is in
 788                  * progress when we access it. it's also possible that during
 789                  * this writeout we put new (partial) data, but then won't
 790                  * be able to proceed in filter_commitrw_write(). thus let's
 791                  * just wait for writeout completion, should be rare enough.
 792                  * -bzzz */
 793                 if (obd->u.filter.fo_writethrough_cache)
 794                         wait_on_page_writeback(lnb->page);
 795                 BUG_ON(PageWriteback(lnb->page));
 796
 797                 /* If the filter writes a partial page, then has the file
 798                  * extended, the client will read in the whole page.  the
 799                  * filter has to be careful to zero the rest of the partial
 800                  * page on disk.  we do it by hand for partial extending
 801                  * writes, send_bio() is responsible for zeroing pages when
 802                  * asked to read unmapped blocks -- brw_kiovec() does this. */
 803                 if (lnb->len != CFS_PAGE_SIZE) {
 804                         __s64 maxidx;
 805
 806                         maxidx = ((i_size_read(dentry->d_inode) +
 807                                    CFS_PAGE_SIZE - 1) >> CFS_PAGE_SHIFT) - 1;
 808                         if (maxidx >= lnb->page->index) {
 809                                 LL_CDEBUG_PAGE(D_PAGE, lnb->page, "write %u @ "
 810                                                LPU64" flg %x before EOF %llu\n",
 811                                                lnb->len, lnb->offset,lnb->flags,
 812                                                i_size_read(dentry->d_inode));
 813                                 filter_iobuf_add_page(obd, iobuf,
 814                                                       dentry->d_inode,
 815                                                       lnb->page);
 816                         } else {
 817                                 long off;
 818                                 char *p = kmap(lnb->page);
 819
 820                                 off = lnb->offset & ~CFS_PAGE_MASK;
 821                                 if (off)
 822                                         memset(p, 0, off);
 823                                 off = (lnb->offset + lnb->len) & ~CFS_PAGE_MASK;
 824                                 if (off)
 825                                         memset(p + off, 0, CFS_PAGE_SIZE - off);
 826                                 kunmap(lnb->page);
 827                         }
 828                 }
 829                 if (lnb->rc == 0)
 830                         tot_bytes += lnb->len;
 831         }
 832         do_gettimeofday(&end);
 833         timediff = cfs_timeval_sub(&end, &start, NULL);
 834         lprocfs_counter_add(obd->obd_stats, LPROC_FILTER_GET_PAGE, timediff);
 835
 836         if (OBD_FAIL_CHECK(OBD_FAIL_OST_NOMEM))
 837                 GOTO(cleanup, rc = -ENOMEM);
 838
 839         /* don't unlock pages to prevent any access */
 840         rc = filter_direct_io(OBD_BRW_READ, dentry, iobuf, exp,
 841                               NULL, NULL, NULL);
 842
 843         fsfilt_check_slow(obd, now, "start_page_write");
 844
 845         if (exp->exp_nid_stats && exp->exp_nid_stats->nid_stats)
 846                 lprocfs_counter_add(exp->exp_nid_stats->nid_stats,
 847                                     LPROC_FILTER_WRITE_BYTES, tot_bytes);
 848         EXIT;
 849 cleanup:
 850         switch(cleanup_phase) {
 851         case 4:
 852                 if (rc) {
 853                         for (i = 0, lnb = res; i < *npages; i++, lnb++) {
 854                                 if (lnb->page != NULL) {
 855                                         unlock_page(lnb->page);
 856                                         page_cache_release(lnb->page);
 857                                         lnb->page = NULL;
 858                                 }
 859                         }
 860                         up_read(&dentry->d_inode->i_alloc_sem);
 861                 }
 862         case 3:
 863                 filter_iobuf_put(&obd->u.filter, iobuf, oti);
 864         case 2:
 865                 pop_ctxt(&saved, &obd->obd_lvfs_ctxt, NULL);
 866                 if (rc)
 867                         f_dput(dentry);
 868                 break;
 869         case 1:
 870                 filter_iobuf_put(&obd->u.filter, iobuf, oti);
 871         case 0:
 872                 spin_lock(&obd->obd_osfs_lock);
 873                 if (oa)
 874                         filter_grant_incoming(exp, oa);
 875                 spin_unlock(&obd->obd_osfs_lock);
 876                 pop_ctxt(&saved, &obd->obd_lvfs_ctxt, NULL);
 877                 break;
 878         default:;
 879         }
 880         return rc;
 881 }
 882
 883 int filter_preprw(int cmd, struct obd_export *exp, struct obdo *oa,
 884                   int objcount, struct obd_ioobj *obj,
 885                   struct niobuf_remote *nb, int *npages,
 886                   struct niobuf_local *res, struct obd_trans_info *oti,
 887                   struct lustre_capa *capa)
 888 {
 889         if (cmd == OBD_BRW_WRITE)
 890                 return filter_preprw_write(cmd, exp, oa, objcount, obj,
 891                                            nb, npages, res, oti, capa);
 892         if (cmd == OBD_BRW_READ)
 893                 return filter_preprw_read(cmd, exp, oa, objcount, obj,
 894                                           nb, npages, res, oti, capa);
 895         LBUG();
 896         return -EPROTO;
 897 }
 898
 899 static int filter_commitrw_read(struct obd_export *exp, struct obdo *oa,
 900                                 int objcount, struct obd_ioobj *obj,
 901                                 struct niobuf_remote *rnb,
 902                                 int npages, struct niobuf_local *res,
 903                                 struct obd_trans_info *oti, int rc)
 904 {
 905         struct filter_obd *fo = &exp->exp_obd->u.filter;
 906         struct inode *inode = NULL;
 907         struct ldlm_res_id res_id;
 908         struct ldlm_resource *resource = NULL;
 909         struct ldlm_namespace *ns = exp->exp_obd->obd_namespace;
 910         struct niobuf_local *lnb;
 911         int i;
 912         ENTRY;
 913
 914         osc_build_res_name(obj->ioo_id, obj->ioo_gr, &res_id);
 915         /* If oa != NULL then filter_preprw_read updated the inode atime
 916          * and we should update the lvb so that other glimpses will also
 917          * get the updated value. bug 5972 */
 918         if (oa && ns && ns->ns_lvbo && ns->ns_lvbo->lvbo_update) {
 919                 resource = ldlm_resource_get(ns, NULL, &res_id, LDLM_EXTENT, 0);
 920
 921                 if (resource != NULL) {
 922                         LDLM_RESOURCE_ADDREF(resource);
 923                         ns->ns_lvbo->lvbo_update(resource, NULL, 0, 1);
 924                         LDLM_RESOURCE_DELREF(resource);
 925                         ldlm_resource_putref(resource);
 926                 }
 927         }
 928
 929         if (res->dentry != NULL)
 930                 inode = res->dentry->d_inode;
 931
 932         for (i = 0, lnb = res; i < npages; i++, lnb++)
 933                 if (lnb->page != NULL)
 934                         page_cache_release(lnb->page);
 935
 936         if (inode && (fo->fo_read_cache == 0 ||
 937                       i_size_read(inode) > fo->fo_readcache_max_filesize))
 938                 filter_truncate_cache(exp->exp_obd, obj, rnb, npages, res,
 939                                       inode);
 940
 941         for (i = 0, lnb = res; i < npages; i++, lnb++)
 942                 lnb->page = NULL;
 943
 944         if (res->dentry != NULL)
 945                 f_dput(res->dentry);
 946         RETURN(rc);
 947 }
 948
 949 void filter_grant_commit(struct obd_export *exp, int niocount,
 950                          struct niobuf_local *res)
 951 {
 952         struct filter_obd *filter = &exp->exp_obd->u.filter;
 953         struct niobuf_local *lnb = res;
 954         unsigned long pending = 0;
 955         int i;
 956
 957         spin_lock(&exp->exp_obd->obd_osfs_lock);
 958         for (i = 0, lnb = res; i < niocount; i++, lnb++)
 959                 pending += lnb->lnb_grant_used;
 960
 961         LASSERTF(exp->exp_filter_data.fed_pending >= pending,
 962                  "%s: cli %s/%p fed_pending: %lu grant_used: %lu\n",
 963                  exp->exp_obd->obd_name, exp->exp_client_uuid.uuid, exp,
 964                  exp->exp_filter_data.fed_pending, pending);
 965         exp->exp_filter_data.fed_pending -= pending;
 966         LASSERTF(filter->fo_tot_granted >= pending,
 967                  "%s: cli %s/%p tot_granted: "LPU64" grant_used: %lu\n",
 968                  exp->exp_obd->obd_name, exp->exp_client_uuid.uuid, exp,
 969                  exp->exp_obd->u.filter.fo_tot_granted, pending);
 970         filter->fo_tot_granted -= pending;
 971         LASSERTF(filter->fo_tot_pending >= pending,
 972                  "%s: cli %s/%p tot_pending: "LPU64" grant_used: %lu\n",
 973                  exp->exp_obd->obd_name, exp->exp_client_uuid.uuid, exp,
 974                  filter->fo_tot_pending, pending);
 975         filter->fo_tot_pending -= pending;
 976
 977         spin_unlock(&exp->exp_obd->obd_osfs_lock);
 978 }
 979
 980 int filter_commitrw(int cmd, struct obd_export *exp, struct obdo *oa,
 981                     int objcount, struct obd_ioobj *obj,
 982                     struct niobuf_remote *nb, int npages,
 983                     struct niobuf_local *res, struct obd_trans_info *oti,
 984                     int rc)
 985 {
 986         if (cmd == OBD_BRW_WRITE)
 987                 return filter_commitrw_write(exp, oa, objcount, obj,
 988                                              nb, npages, res, oti, rc);
 989         if (cmd == OBD_BRW_READ)
 990                 return filter_commitrw_read(exp, oa, objcount, obj,
 991                                             nb, npages, res, oti, rc);
 992         LBUG();
 993         return -EPROTO;
 994 }
 995
 996 int filter_brw(int cmd, struct obd_export *exp, struct obd_info *oinfo,
 997                obd_count oa_bufs, struct brw_page *pga,
 998                struct obd_trans_info *oti)
 999 {
1000         struct obd_ioobj ioo;
1001         struct niobuf_local *lnb;
1002         struct niobuf_remote *rnb;
1003         obd_count i;
1004         int ret = 0, npages;
1005         ENTRY;
1006
1007         OBD_ALLOC(lnb, oa_bufs * sizeof(struct niobuf_local));
1008         OBD_ALLOC(rnb, oa_bufs * sizeof(struct niobuf_remote));
1009
1010         if (lnb == NULL || rnb == NULL)
1011                 GOTO(out, ret = -ENOMEM);
1012
1013         for (i = 0; i < oa_bufs; i++) {
1014                 lnb[i].page = pga[i].pg;
1015                 rnb[i].offset = pga[i].off;
1016                 rnb[i].len = pga[i].count;
1017         }
1018
1019         obdo_to_ioobj(oinfo->oi_oa, &ioo);
1020         ioo.ioo_bufcnt = oa_bufs;
1021
1022         npages = oa_bufs;
1023         ret = filter_preprw(cmd, exp, oinfo->oi_oa, 1, &ioo,
1024                             rnb, &npages, lnb, oti, oinfo_capa(oinfo));
1025         if (ret != 0)
1026                 GOTO(out, ret);
1027         LASSERTF(oa_bufs == npages, "%u != %u\n", oa_bufs, npages);
1028
1029         ret = filter_commitrw(cmd, exp, oinfo->oi_oa, 1, &ioo, rnb,
1030                               npages, lnb, oti, ret);
1031
1032 out:
1033         if (lnb)
1034                 OBD_FREE(lnb, oa_bufs * sizeof(struct niobuf_local));
1035         if (rnb)
1036                 OBD_FREE(rnb, oa_bufs * sizeof(struct niobuf_remote));
1037         RETURN(ret);
1038 }