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 (c) 2003, 2010, Oracle and/or its affiliates. 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                 cfs_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,
 156                                cfs_time_current_64() - CFS_HZ)) {
 157 restat:
 158                 rc = fsfilt_statfs(obd, obd->u.obt.obt_sb,
 159                                    cfs_time_current_64() + CFS_HZ);
 160                 if (rc) /* N.B. statfs can't really fail */
 161                         RETURN(0);
 162                 statfs_done = 1;
 163         }
 164
 165         avail = obd->obd_osfs.os_bavail;
 166         left = avail - (avail >> (blockbits - 3)); /* (d)indirect */
 167         if (left > GRANT_FOR_LLOG(obd)) {
 168                 left = (left - GRANT_FOR_LLOG(obd)) << blockbits;
 169         } else {
 170                 left = 0 /* << blockbits */;
 171         }
 172
 173         if (!statfs_done && left < 32 * FILTER_GRANT_CHUNK + tot_granted) {
 174                 CDEBUG(D_CACHE, "fs has no space left and statfs too old\n");
 175                 goto restat;
 176         }
 177
 178         if (left >= tot_granted) {
 179                 left -= tot_granted;
 180         } else {
 181                 if (left < tot_granted - obd->u.filter.fo_tot_pending) {
 182                         CERROR("%s: cli %s/%p grant "LPU64" > available "
 183                                LPU64" and pending "LPU64"\n", obd->obd_name,
 184                                exp->exp_client_uuid.uuid, exp, tot_granted,
 185                                left, obd->u.filter.fo_tot_pending);
 186                 }
 187                 left = 0;
 188         }
 189
 190         CDEBUG(D_CACHE, "%s: cli %s/%p free: "LPU64" avail: "LPU64" grant "LPU64
 191                " left: "LPU64" pending: "LPU64"\n", obd->obd_name,
 192                exp->exp_client_uuid.uuid, exp,
 193                obd->obd_osfs.os_bfree << blockbits, avail << blockbits,
 194                tot_granted, left, obd->u.filter.fo_tot_pending);
 195
 196         return left;
 197 }
 198
 199 /* Calculate how much grant space to allocate to this client, based on how
 200  * much space is currently free and how much of that is already granted.
 201  *
 202  * if @conservative != 0, we limit the maximum grant to FILTER_GRANT_CHUNK;
 203  * otherwise we'll satisfy the requested amount as possible as we can, this
 204  * is usually due to client reconnect.
 205  *
 206  * Caller must hold obd_osfs_lock. */
 207 long filter_grant(struct obd_export *exp, obd_size current_grant,
 208                   obd_size want, obd_size fs_space_left, int conservative)
 209 {
 210         struct obd_device *obd = exp->exp_obd;
 211         struct filter_export_data *fed = &exp->exp_filter_data;
 212         int blockbits = obd->u.obt.obt_sb->s_blocksize_bits;
 213         __u64 grant = 0;
 214
 215         LASSERT_SPIN_LOCKED(&obd->obd_osfs_lock);
 216
 217         /* Grant some fraction of the client's requested grant space so that
 218          * they are not always waiting for write credits (not all of it to
 219          * avoid overgranting in face of multiple RPCs in flight).  This
 220          * essentially will be able to control the OSC_MAX_RIF for a client.
 221          *
 222          * If we do have a large disparity between what the client thinks it
 223          * has and what we think it has, don't grant very much and let the
 224          * client consume its grant first.  Either it just has lots of RPCs
 225          * in flight, or it was evicted and its grants will soon be used up. */
 226         if (want > 0x7fffffff) {
 227                 CERROR("%s: client %s/%p requesting > 2GB grant "LPU64"\n",
 228                        obd->obd_name, exp->exp_client_uuid.uuid, exp, want);
 229         } else if (current_grant < want &&
 230                    current_grant < fed->fed_grant + FILTER_GRANT_CHUNK) {
 231                 grant = min(want + (1 << blockbits) - 1, fs_space_left / 8);
 232                 grant &= ~((1ULL << blockbits) - 1);
 233
 234                 if (grant) {
 235                         if (grant > FILTER_GRANT_CHUNK && conservative)
 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                                 cfs_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));
 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 invalidate above doesn't work during read because lnet pins pages.
 345  * The truncate is used here instead to drop pages from cache
 346  */
 347 void filter_release_cache(struct obd_device *obd, struct obd_ioobj *obj,
 348                           struct niobuf_remote *rnb, struct inode *inode)
 349 {
 350         int i;
 351
 352         LASSERT(inode != NULL);
 353         for (i = 0; i < obj->ioo_bufcnt; i++, rnb++) {
 354 #ifdef HAVE_TRUNCATE_RANGE
 355                 /* remove pages in which range is fit */
 356                 truncate_inode_pages_range(inode->i_mapping,
 357                                            rnb->offset & CFS_PAGE_MASK,
 358                                            (rnb->offset + rnb->len - 1) |
 359                                            ~CFS_PAGE_MASK);
 360 #else
 361                 /* use invalidate for old kernels */
 362                 invalidate_mapping_pages(inode->i_mapping,
 363                                          rnb->offset >> CFS_PAGE_SHIFT,
 364                                          (rnb->offset + rnb->len) >>
 365                                          CFS_PAGE_SHIFT);
 366 #endif
 367         }
 368 }
 369
 370 static int filter_preprw_read(int cmd, struct obd_export *exp, struct obdo *oa,
 371                               int objcount, struct obd_ioobj *obj,
 372                               struct niobuf_remote *nb,
 373                               int *npages, struct niobuf_local *res,
 374                               struct obd_trans_info *oti,
 375                               struct lustre_capa *capa)
 376 {
 377         struct obd_device *obd = exp->exp_obd;
 378         struct timeval start, end;
 379         struct lvfs_run_ctxt saved;
 380         struct niobuf_local *lnb;
 381         struct dentry *dentry = NULL;
 382         struct inode *inode = NULL;
 383         void *iobuf = NULL;
 384         int rc = 0, i, tot_bytes = 0;
 385         unsigned long now = jiffies;
 386         long timediff;
 387         loff_t isize;
 388         ENTRY;
 389
 390         /* We are currently not supporting multi-obj BRW_READ RPCS at all.
 391          * When we do this function's dentry cleanup will need to be fixed.
 392          * These values are verified in ost_brw_write() from the wire. */
 393         LASSERTF(objcount == 1, "%d\n", objcount);
 394         LASSERTF(obj->ioo_bufcnt > 0, "%d\n", obj->ioo_bufcnt);
 395
 396         rc = filter_auth_capa(exp, NULL, oa->o_seq, capa,
 397                               CAPA_OPC_OSS_READ);
 398         if (rc)
 399                 RETURN(rc);
 400
 401         if (oa && oa->o_valid & OBD_MD_FLGRANT) {
 402                 cfs_spin_lock(&obd->obd_osfs_lock);
 403                 filter_grant_incoming(exp, oa);
 404
 405                 if (!(oa->o_flags & OBD_FL_SHRINK_GRANT))
 406                         oa->o_grant = 0;
 407                 cfs_spin_unlock(&obd->obd_osfs_lock);
 408         }
 409
 410         iobuf = filter_iobuf_get(&obd->u.filter, oti);
 411         if (IS_ERR(iobuf))
 412                 RETURN(PTR_ERR(iobuf));
 413
 414         push_ctxt(&saved, &obd->obd_lvfs_ctxt, NULL);
 415         dentry = filter_oa2dentry(obd, &oa->o_oi);
 416         if (IS_ERR(dentry)) {
 417                 rc = PTR_ERR(dentry);
 418                 dentry = NULL;
 419                 GOTO(cleanup, rc);
 420         }
 421
 422         inode = dentry->d_inode;
 423         isize = i_size_read(inode);
 424
 425         obdo_to_inode(inode, oa, OBD_MD_FLATIME);
 426
 427         rc = filter_map_remote_to_local(objcount, obj, nb, npages, res);
 428         if (rc)
 429                 GOTO(cleanup, rc);
 430
 431         fsfilt_check_slow(obd, now, "preprw_read setup");
 432
 433         /* find pages for all segments, fill array with them */
 434         cfs_gettimeofday(&start);
 435         for (i = 0, lnb = res; i < *npages; i++, lnb++) {
 436
 437                 lnb->dentry = dentry;
 438
 439                 if (isize <= lnb->offset)
 440                         /* If there's no more data, abort early.  lnb->rc == 0,
 441                          * so it's easy to detect later. */
 442                         break;
 443
 444                 lnb->page = filter_get_page(obd, inode, lnb->offset, 0);
 445                 if (lnb->page == NULL)
 446                         GOTO(cleanup, rc = -ENOMEM);
 447
 448                 lprocfs_counter_add(obd->obd_stats, LPROC_FILTER_CACHE_ACCESS, 1);
 449
 450                 if (isize < lnb->offset + lnb->len - 1)
 451                         lnb->rc = isize - lnb->offset;
 452                 else
 453                         lnb->rc = lnb->len;
 454
 455                 tot_bytes += lnb->rc;
 456
 457                 if (PageUptodate(lnb->page)) {
 458                         lprocfs_counter_add(obd->obd_stats,
 459                                             LPROC_FILTER_CACHE_HIT, 1);
 460                         continue;
 461                 }
 462
 463                 lprocfs_counter_add(obd->obd_stats, LPROC_FILTER_CACHE_MISS, 1);
 464                 filter_iobuf_add_page(obd, iobuf, inode, lnb->page);
 465         }
 466         cfs_gettimeofday(&end);
 467         timediff = cfs_timeval_sub(&end, &start, NULL);
 468         lprocfs_counter_add(obd->obd_stats, LPROC_FILTER_GET_PAGE, timediff);
 469
 470         if (OBD_FAIL_CHECK(OBD_FAIL_OST_NOMEM))
 471                 GOTO(cleanup, rc = -ENOMEM);
 472
 473         fsfilt_check_slow(obd, now, "start_page_read");
 474
 475         rc = filter_direct_io(OBD_BRW_READ, dentry, iobuf,
 476                               exp, NULL, NULL, NULL);
 477         if (rc)
 478                 GOTO(cleanup, rc);
 479
 480         lprocfs_counter_add(obd->obd_stats, LPROC_FILTER_READ_BYTES, tot_bytes);
 481
 482         if (exp->exp_nid_stats && exp->exp_nid_stats->nid_stats)
 483                 lprocfs_counter_add(exp->exp_nid_stats->nid_stats,
 484                                     LPROC_FILTER_READ_BYTES, tot_bytes);
 485
 486         EXIT;
 487
 488  cleanup:
 489         /* unlock pages to allow access from concurrent OST_READ */
 490         for (i = 0, lnb = res; i < *npages; i++, lnb++) {
 491                 if (lnb->page) {
 492                         LASSERT(PageLocked(lnb->page));
 493                         unlock_page(lnb->page);
 494
 495                         if (rc) {
 496                                 page_cache_release(lnb->page);
 497                                 lnb->page = NULL;
 498                         }
 499                 }
 500         }
 501
 502         if (rc != 0) {
 503                 if (dentry != NULL)
 504                         f_dput(dentry);
 505         }
 506
 507         filter_iobuf_put(&obd->u.filter, iobuf, oti);
 508
 509         pop_ctxt(&saved, &obd->obd_lvfs_ctxt, NULL);
 510         if (rc)
 511                 CERROR("io error %d\n", rc);
 512
 513         return rc;
 514 }
 515
 516 /* When clients have dirtied as much space as they've been granted they
 517  * fall through to sync writes.  These sync writes haven't been expressed
 518  * in grants and need to error with ENOSPC when there isn't room in the
 519  * filesystem for them after grants are taken into account.  However,
 520  * writeback of the dirty data that was already granted space can write
 521  * right on through.
 522  *
 523  * Caller must hold obd_osfs_lock. */
 524 static int filter_grant_check(struct obd_export *exp, struct obdo *oa,
 525                               int objcount, struct fsfilt_objinfo *fso,
 526                               int niocount, struct niobuf_local *lnb,
 527                               obd_size *left, struct inode *inode)
 528 {
 529         struct filter_export_data *fed = &exp->exp_filter_data;
 530         int blocksize = exp->exp_obd->u.obt.obt_sb->s_blocksize;
 531         unsigned long used = 0, ungranted = 0, using;
 532         int i, rc = -ENOSPC, obj, n = 0;
 533         int resend = oa->o_valid & OBD_FL_RECOV_RESEND;
 534
 535         LASSERT_SPIN_LOCKED(&exp->exp_obd->obd_osfs_lock);
 536
 537         if (resend)
 538                 CDEBUG(D_CACHE, "Recoverable resend arrived, skipping "
 539                        "accounting\n");
 540
 541         for (obj = 0; obj < objcount; obj++) {
 542                 for (i = 0; i < fso[obj].fso_bufcnt; i++, n++) {
 543                         int tmp, bytes;
 544
 545                         /* should match the code in osc_exit_cache */
 546                         bytes = lnb[n].len;
 547                         bytes += lnb[n].offset & (blocksize - 1);
 548                         tmp = (lnb[n].offset + lnb[n].len) & (blocksize - 1);
 549                         if (tmp)
 550                                 bytes += blocksize - tmp;
 551
 552                         if ((lnb[n].flags & OBD_BRW_FROM_GRANT) &&
 553                             (oa->o_valid & OBD_MD_FLGRANT)) {
 554                                 if (resend) {
 555                                         lnb[n].flags |= OBD_BRW_GRANTED;
 556                                         rc = 0;
 557                                         continue;
 558                                 } else if (fed->fed_grant < used + bytes) {
 559                                         CDEBUG(D_CACHE,
 560                                                "%s: cli %s/%p claims %ld+%d "
 561                                                "GRANT, real grant %lu idx %d\n",
 562                                                exp->exp_obd->obd_name,
 563                                                exp->exp_client_uuid.uuid, exp,
 564                                                used, bytes, fed->fed_grant, n);
 565                                 } else {
 566                                         used += bytes;
 567                                         lnb[n].flags |= OBD_BRW_GRANTED;
 568                                         lnb[n].lnb_grant_used = bytes;
 569                                         CDEBUG(0, "idx %d used=%lu\n", n, used);
 570                                         rc = 0;
 571                                         continue;
 572                                 }
 573                         }
 574                         if (*left > ungranted + bytes) {
 575                                 /* if enough space, pretend it was granted */
 576                                 ungranted += bytes;
 577                                 lnb[n].flags |= OBD_BRW_GRANTED;
 578                                 lnb[n].lnb_grant_used = bytes;
 579                                 CDEBUG(0, "idx %d ungranted=%lu\n",n,ungranted);
 580                                 rc = 0;
 581                                 continue;
 582                         }
 583
 584                         /* We can't check for already-mapped blocks here, as
 585                          * it requires dropping the osfs lock to do the bmap.
 586                          * Instead, we return ENOSPC and in that case we need
 587                          * to go through and verify if all of the blocks not
 588                          * marked BRW_GRANTED are already mapped and we can
 589                          * ignore this error. */
 590                         lnb[n].rc = -ENOSPC;
 591                         lnb[n].flags &= ~OBD_BRW_GRANTED;
 592                         CDEBUG(D_CACHE,"%s: cli %s/%p idx %d no space for %d\n",
 593                                exp->exp_obd->obd_name,
 594                                exp->exp_client_uuid.uuid, exp, n, bytes);
 595                 }
 596         }
 597
 598         /* Now substract what client have used already.  We don't subtract
 599          * this from the tot_granted yet, so that other client's can't grab
 600          * that space before we have actually allocated our blocks.  That
 601          * happens in filter_grant_commit() after the writes are done. */
 602         *left -= ungranted;
 603         fed->fed_grant -= used;
 604         fed->fed_pending += used + ungranted;
 605         exp->exp_obd->u.filter.fo_tot_granted += ungranted;
 606         exp->exp_obd->u.filter.fo_tot_pending += used + ungranted;
 607
 608         CDEBUG(D_CACHE,
 609                "%s: cli %s/%p used: %lu ungranted: %lu grant: %lu dirty: %lu\n",
 610                exp->exp_obd->obd_name, exp->exp_client_uuid.uuid, exp, used,
 611                ungranted, fed->fed_grant, fed->fed_dirty);
 612
 613         /* Rough calc in case we don't refresh cached statfs data */
 614         using = (used + ungranted + 1 ) >>
 615                 exp->exp_obd->u.obt.obt_sb->s_blocksize_bits;
 616         if (exp->exp_obd->obd_osfs.os_bavail > using)
 617                 exp->exp_obd->obd_osfs.os_bavail -= using;
 618         else
 619                 exp->exp_obd->obd_osfs.os_bavail = 0;
 620
 621         if (fed->fed_dirty < used) {
 622                 CERROR("%s: cli %s/%p claims used %lu > fed_dirty %lu\n",
 623                        exp->exp_obd->obd_name, exp->exp_client_uuid.uuid, exp,
 624                        used, fed->fed_dirty);
 625                 used = fed->fed_dirty;
 626         }
 627         exp->exp_obd->u.filter.fo_tot_dirty -= used;
 628         fed->fed_dirty -= used;
 629
 630         if (fed->fed_dirty < 0 || fed->fed_grant < 0 || fed->fed_pending < 0) {
 631                 CERROR("%s: cli %s/%p dirty %ld pend %ld grant %ld\n",
 632                        exp->exp_obd->obd_name, exp->exp_client_uuid.uuid, exp,
 633                        fed->fed_dirty, fed->fed_pending, fed->fed_grant);
 634                 cfs_spin_unlock(&exp->exp_obd->obd_osfs_lock);
 635                 LBUG();
 636         }
 637         return rc;
 638 }
 639
 640 /* If we ever start to support multi-object BRW RPCs, we will need to get locks
 641  * on mulitple inodes.  That isn't all, because there still exists the
 642  * possibility of a truncate starting a new transaction while holding the ext3
 643  * rwsem = write while some writes (which have started their transactions here)
 644  * blocking on the ext3 rwsem = read => lock inversion.
 645  *
 646  * The handling gets very ugly when dealing with locked pages.  It may be easier
 647  * to just get rid of the locked page code (which has problems of its own) and
 648  * either discover we do not need it anymore (i.e. it was a symptom of another
 649  * bug) or ensure we get the page locks in an appropriate order. */
 650 static int filter_preprw_write(int cmd, struct obd_export *exp, struct obdo *oa,
 651                                int objcount, struct obd_ioobj *obj,
 652                                struct niobuf_remote *nb, int *npages,
 653                                struct niobuf_local *res,
 654                                struct obd_trans_info *oti,
 655                                struct lustre_capa *capa)
 656 {
 657         struct obd_device *obd = exp->exp_obd;
 658         struct timeval start, end;
 659         struct lvfs_run_ctxt saved;
 660         struct niobuf_local *lnb = res;
 661         struct fsfilt_objinfo fso;
 662         struct filter_mod_data *fmd;
 663         struct dentry *dentry = NULL;
 664         void *iobuf;
 665         obd_size left;
 666         unsigned long now = jiffies, timediff;
 667         int rc = 0, i, tot_bytes = 0, cleanup_phase = 0, localreq = 0;
 668         ENTRY;
 669         LASSERT(objcount == 1);
 670         LASSERT(obj->ioo_bufcnt > 0);
 671
 672         rc = filter_auth_capa(exp, NULL, oa->o_seq, capa,
 673                               CAPA_OPC_OSS_WRITE);
 674         if (rc)
 675                 RETURN(rc);
 676
 677         if (exp->exp_connection &&
 678             exp->exp_connection->c_peer.nid == exp->exp_connection->c_self)
 679                 localreq = 1;
 680
 681         push_ctxt(&saved, &obd->obd_lvfs_ctxt, NULL);
 682         iobuf = filter_iobuf_get(&obd->u.filter, oti);
 683         if (IS_ERR(iobuf))
 684                 GOTO(cleanup, rc = PTR_ERR(iobuf));
 685         cleanup_phase = 1;
 686
 687         dentry = filter_fid2dentry(obd, NULL, obj->ioo_seq,
 688                                    obj->ioo_id);
 689         if (IS_ERR(dentry))
 690                 GOTO(cleanup, rc = PTR_ERR(dentry));
 691         cleanup_phase = 2;
 692
 693         if (dentry->d_inode == NULL) {
 694                 CERROR("%s: trying to BRW to non-existent file "LPU64"\n",
 695                        obd->obd_name, obj->ioo_id);
 696                 GOTO(cleanup, rc = -ENOENT);
 697         }
 698
 699         if (oa->o_valid & (OBD_MD_FLUID | OBD_MD_FLGID) &&
 700             dentry->d_inode->i_mode & (S_ISUID | S_ISGID)) {
 701                 rc = filter_capa_fixoa(exp, oa, oa->o_seq, capa);
 702                 if (rc)
 703                         GOTO(cleanup, rc);
 704         }
 705
 706         rc = filter_map_remote_to_local(objcount, obj, nb, npages, res);
 707         if (rc)
 708                 GOTO(cleanup, rc);
 709
 710         fsfilt_check_slow(obd, now, "preprw_write setup");
 711
 712         /* Filter truncate first locks i_mutex then partially truncated
 713          * page, filter write code first locks pages then take
 714          * i_mutex.  To avoid a deadlock in case of concurrent
 715          * punch/write requests from one client, filter writes and
 716          * filter truncates are serialized by i_alloc_sem, allowing
 717          * multiple writes or single truncate. */
 718         down_read(&dentry->d_inode->i_alloc_sem);
 719
 720         /* Don't update inode timestamps if this write is older than a
 721          * setattr which modifies the timestamps. b=10150 */
 722         /* XXX when we start having persistent reservations this needs to
 723          * be changed to filter_fmd_get() to create the fmd if it doesn't
 724          * already exist so we can store the reservation handle there. */
 725         fmd = filter_fmd_find(exp, obj->ioo_id, obj->ioo_seq);
 726
 727         LASSERT(oa != NULL);
 728         cfs_spin_lock(&obd->obd_osfs_lock);
 729         filter_grant_incoming(exp, oa);
 730         if (fmd && fmd->fmd_mactime_xid > oti->oti_xid)
 731                 oa->o_valid &= ~(OBD_MD_FLMTIME | OBD_MD_FLCTIME |
 732                                  OBD_MD_FLATIME);
 733         else
 734                 obdo_to_inode(dentry->d_inode, oa, OBD_MD_FLATIME |
 735                               OBD_MD_FLMTIME | OBD_MD_FLCTIME);
 736         cleanup_phase = 3;
 737
 738         left = filter_grant_space_left(exp);
 739
 740         fso.fso_dentry = dentry;
 741         fso.fso_bufcnt = *npages;
 742
 743         rc = filter_grant_check(exp, oa, objcount, &fso, *npages, res,
 744                                 &left, dentry->d_inode);
 745
 746         /* do not zero out oa->o_valid as it is used in filter_commitrw_write()
 747          * for setting UID/GID and fid EA in first write time. */
 748         /* If OBD_FL_SHRINK_GRANT is set, the client just returned us some grant
 749          * so no sense in allocating it some more. We either return the grant
 750          * back to the client if we have plenty of space or we don't return
 751          * anything if we are short. This was decided in filter_grant_incoming*/
 752         if (oa->o_valid & OBD_MD_FLGRANT &&!(oa->o_valid & OBD_FL_SHRINK_GRANT))
 753                 oa->o_grant = filter_grant(exp, oa->o_grant, oa->o_undirty,
 754                                            left, 1);
 755
 756         cfs_spin_unlock(&obd->obd_osfs_lock);
 757         filter_fmd_put(exp, fmd);
 758
 759         OBD_FAIL_TIMEOUT(OBD_FAIL_OST_BRW_PAUSE_BULK2, (obd_timeout + 1) / 4);
 760
 761         if (rc)
 762                 GOTO(cleanup, rc);
 763         cleanup_phase = 4;
 764
 765         cfs_gettimeofday(&start);
 766         for (i = 0, lnb = res; i < *npages; i++, lnb++) {
 767
 768                 /* We still set up for ungranted pages so that granted pages
 769                  * can be written to disk as they were promised, and portals
 770                  * needs to keep the pages all aligned properly. */
 771                 lnb->dentry = dentry;
 772
 773                 lnb->page = filter_get_page(obd, dentry->d_inode, lnb->offset,
 774                                             localreq);
 775                 if (lnb->page == NULL)
 776                         GOTO(cleanup, rc = -ENOMEM);
 777
 778                 /* DLM locking protects us from write and truncate competing
 779                  * for same region, but truncate can leave dirty page in the
 780                  * cache. it's possible the writeout on a such a page is in
 781                  * progress when we access it. it's also possible that during
 782                  * this writeout we put new (partial) data, but then won't
 783                  * be able to proceed in filter_commitrw_write(). thus let's
 784                  * just wait for writeout completion, should be rare enough.
 785                  * -bzzz */
 786                 wait_on_page_writeback(lnb->page);
 787                 BUG_ON(PageWriteback(lnb->page));
 788
 789                 /* If the filter writes a partial page, then has the file
 790                  * extended, the client will read in the whole page.  the
 791                  * filter has to be careful to zero the rest of the partial
 792                  * page on disk.  we do it by hand for partial extending
 793                  * writes, send_bio() is responsible for zeroing pages when
 794                  * asked to read unmapped blocks -- brw_kiovec() does this. */
 795                 if (lnb->len != CFS_PAGE_SIZE) {
 796                         __s64 maxidx;
 797
 798                         maxidx = ((i_size_read(dentry->d_inode) +
 799                                    CFS_PAGE_SIZE - 1) >> CFS_PAGE_SHIFT) - 1;
 800                         if (maxidx >= lnb->page->index) {
 801                                 LL_CDEBUG_PAGE(D_PAGE, lnb->page, "write %u @ "
 802                                                LPU64" flg %x before EOF %llu\n",
 803                                                lnb->len, lnb->offset,lnb->flags,
 804                                                i_size_read(dentry->d_inode));
 805                                 filter_iobuf_add_page(obd, iobuf,
 806                                                       dentry->d_inode,
 807                                                       lnb->page);
 808                         } else {
 809                                 long off;
 810                                 char *p = kmap(lnb->page);
 811
 812                                 off = lnb->offset & ~CFS_PAGE_MASK;
 813                                 if (off)
 814                                         memset(p, 0, off);
 815                                 off = (lnb->offset + lnb->len) & ~CFS_PAGE_MASK;
 816                                 if (off)
 817                                         memset(p + off, 0, CFS_PAGE_SIZE - off);
 818                                 kunmap(lnb->page);
 819                         }
 820                 }
 821                 if (lnb->rc == 0)
 822                         tot_bytes += lnb->len;
 823         }
 824         cfs_gettimeofday(&end);
 825         timediff = cfs_timeval_sub(&end, &start, NULL);
 826         lprocfs_counter_add(obd->obd_stats, LPROC_FILTER_GET_PAGE, timediff);
 827
 828         if (OBD_FAIL_CHECK(OBD_FAIL_OST_NOMEM))
 829                 GOTO(cleanup, rc = -ENOMEM);
 830
 831         /* don't unlock pages to prevent any access */
 832         rc = filter_direct_io(OBD_BRW_READ, dentry, iobuf, exp,
 833                               NULL, NULL, NULL);
 834
 835         fsfilt_check_slow(obd, now, "start_page_write");
 836
 837         lprocfs_counter_add(obd->obd_stats, LPROC_FILTER_WRITE_BYTES,
 838                             tot_bytes);
 839
 840         if (exp->exp_nid_stats && exp->exp_nid_stats->nid_stats)
 841                 lprocfs_counter_add(exp->exp_nid_stats->nid_stats,
 842                                     LPROC_FILTER_WRITE_BYTES, tot_bytes);
 843         EXIT;
 844 cleanup:
 845         switch(cleanup_phase) {
 846         case 4:
 847                 if (rc) {
 848                         for (i = 0, lnb = res; i < *npages; i++, lnb++) {
 849                                 if (lnb->page != NULL) {
 850                                         unlock_page(lnb->page);
 851                                         page_cache_release(lnb->page);
 852                                         lnb->page = NULL;
 853                                 }
 854                         }
 855                 }
 856         case 3:
 857                 if (rc)
 858                         up_read(&dentry->d_inode->i_alloc_sem);
 859
 860                 filter_iobuf_put(&obd->u.filter, iobuf, oti);
 861         case 2:
 862                 pop_ctxt(&saved, &obd->obd_lvfs_ctxt, NULL);
 863                 if (rc)
 864                         f_dput(dentry);
 865                 break;
 866         case 1:
 867                 filter_iobuf_put(&obd->u.filter, iobuf, oti);
 868         case 0:
 869                 cfs_spin_lock(&obd->obd_osfs_lock);
 870                 if (oa)
 871                         filter_grant_incoming(exp, oa);
 872                 cfs_spin_unlock(&obd->obd_osfs_lock);
 873                 pop_ctxt(&saved, &obd->obd_lvfs_ctxt, NULL);
 874                 break;
 875         default:;
 876         }
 877         return rc;
 878 }
 879
 880 int filter_preprw(int cmd, struct obd_export *exp, struct obdo *oa,
 881                   int objcount, struct obd_ioobj *obj,
 882                   struct niobuf_remote *nb, int *npages,
 883                   struct niobuf_local *res, struct obd_trans_info *oti,
 884                   struct lustre_capa *capa)
 885 {
 886         if (cmd == OBD_BRW_WRITE)
 887                 return filter_preprw_write(cmd, exp, oa, objcount, obj,
 888                                            nb, npages, res, oti, capa);
 889         if (cmd == OBD_BRW_READ)
 890                 return filter_preprw_read(cmd, exp, oa, objcount, obj,
 891                                           nb, npages, res, oti, capa);
 892         LBUG();
 893         return -EPROTO;
 894 }
 895
 896 static int filter_commitrw_read(struct obd_export *exp, struct obdo *oa,
 897                                 int objcount, struct obd_ioobj *obj,
 898                                 struct niobuf_remote *rnb,
 899                                 int npages, struct niobuf_local *res,
 900                                 struct obd_trans_info *oti, int rc)
 901 {
 902         struct filter_obd *fo = &exp->exp_obd->u.filter;
 903         struct inode *inode = NULL;
 904         struct ldlm_res_id res_id;
 905         struct ldlm_resource *resource = NULL;
 906         struct ldlm_namespace *ns = exp->exp_obd->obd_namespace;
 907         struct niobuf_local *lnb;
 908         int i;
 909         ENTRY;
 910
 911         osc_build_res_name(obj->ioo_id, obj->ioo_seq, &res_id);
 912         /* If oa != NULL then filter_preprw_read updated the inode atime
 913          * and we should update the lvb so that other glimpses will also
 914          * get the updated value. bug 5972 */
 915         if (oa && ns && ns->ns_lvbo && ns->ns_lvbo->lvbo_update) {
 916                 resource = ldlm_resource_get(ns, NULL, &res_id, LDLM_EXTENT, 0);
 917
 918                 if (resource != NULL) {
 919                         LDLM_RESOURCE_ADDREF(resource);
 920                         ns->ns_lvbo->lvbo_update(resource, NULL, 1);
 921                         LDLM_RESOURCE_DELREF(resource);
 922                         ldlm_resource_putref(resource);
 923                 }
 924         }
 925
 926         if (res->dentry != NULL)
 927                 inode = res->dentry->d_inode;
 928
 929         for (i = 0, lnb = res; i < npages; i++, lnb++) {
 930                 if (lnb->page != NULL) {
 931                         page_cache_release(lnb->page);
 932                         lnb->page = NULL;
 933                 }
 934         }
 935         if (inode && (fo->fo_read_cache == 0 ||
 936                       i_size_read(inode) > fo->fo_readcache_max_filesize))
 937                 filter_release_cache(exp->exp_obd, obj, rnb, inode);
 938
 939         if (res->dentry != NULL)
 940                 f_dput(res->dentry);
 941         RETURN(rc);
 942 }
 943
 944 void filter_grant_commit(struct obd_export *exp, int niocount,
 945                          struct niobuf_local *res)
 946 {
 947         struct filter_obd *filter = &exp->exp_obd->u.filter;
 948         struct niobuf_local *lnb = res;
 949         unsigned long pending = 0;
 950         int i;
 951
 952         cfs_spin_lock(&exp->exp_obd->obd_osfs_lock);
 953         for (i = 0, lnb = res; i < niocount; i++, lnb++)
 954                 pending += lnb->lnb_grant_used;
 955
 956         LASSERTF(exp->exp_filter_data.fed_pending >= pending,
 957                  "%s: cli %s/%p fed_pending: %lu grant_used: %lu\n",
 958                  exp->exp_obd->obd_name, exp->exp_client_uuid.uuid, exp,
 959                  exp->exp_filter_data.fed_pending, pending);
 960         exp->exp_filter_data.fed_pending -= pending;
 961         LASSERTF(filter->fo_tot_granted >= pending,
 962                  "%s: cli %s/%p tot_granted: "LPU64" grant_used: %lu\n",
 963                  exp->exp_obd->obd_name, exp->exp_client_uuid.uuid, exp,
 964                  exp->exp_obd->u.filter.fo_tot_granted, pending);
 965         filter->fo_tot_granted -= pending;
 966         LASSERTF(filter->fo_tot_pending >= pending,
 967                  "%s: cli %s/%p tot_pending: "LPU64" grant_used: %lu\n",
 968                  exp->exp_obd->obd_name, exp->exp_client_uuid.uuid, exp,
 969                  filter->fo_tot_pending, pending);
 970         filter->fo_tot_pending -= pending;
 971
 972         cfs_spin_unlock(&exp->exp_obd->obd_osfs_lock);
 973 }
 974
 975 int filter_commitrw(int cmd, struct obd_export *exp, struct obdo *oa,
 976                     int objcount, struct obd_ioobj *obj,
 977                     struct niobuf_remote *nb, int npages,
 978                     struct niobuf_local *res, struct obd_trans_info *oti,
 979                     int rc)
 980 {
 981         if (cmd == OBD_BRW_WRITE)
 982                 return filter_commitrw_write(exp, oa, objcount, obj,
 983                                              nb, npages, res, oti, rc);
 984         if (cmd == OBD_BRW_READ)
 985                 return filter_commitrw_read(exp, oa, objcount, obj,
 986                                             nb, npages, res, oti, rc);
 987         LBUG();
 988         return -EPROTO;
 989 }
 990
 991 int filter_brw(int cmd, struct obd_export *exp, struct obd_info *oinfo,
 992                obd_count oa_bufs, struct brw_page *pga,
 993                struct obd_trans_info *oti)
 994 {
 995         struct obd_ioobj ioo;
 996         struct niobuf_local *lnb;
 997         struct niobuf_remote *rnb;
 998         obd_count i;
 999         int ret = 0, npages;
1000         ENTRY;
1001
1002         OBD_ALLOC(lnb, oa_bufs * sizeof(struct niobuf_local));
1003         OBD_ALLOC(rnb, oa_bufs * sizeof(struct niobuf_remote));
1004
1005         if (lnb == NULL || rnb == NULL)
1006                 GOTO(out, ret = -ENOMEM);
1007
1008         for (i = 0; i < oa_bufs; i++) {
1009                 lnb[i].page = pga[i].pg;
1010                 rnb[i].offset = pga[i].off;
1011                 rnb[i].len = pga[i].count;
1012         }
1013
1014         obdo_to_ioobj(oinfo->oi_oa, &ioo);
1015         ioo.ioo_bufcnt = oa_bufs;
1016
1017         npages = oa_bufs;
1018         ret = filter_preprw(cmd, exp, oinfo->oi_oa, 1, &ioo,
1019                             rnb, &npages, lnb, oti, oinfo_capa(oinfo));
1020         if (ret != 0)
1021                 GOTO(out, ret);
1022         LASSERTF(oa_bufs == npages, "%u != %u\n", oa_bufs, npages);
1023
1024         ret = filter_commitrw(cmd, exp, oinfo->oi_oa, 1, &ioo, rnb,
1025                               npages, lnb, oti, ret);
1026
1027 out:
1028         if (lnb)
1029                 OBD_FREE(lnb, oa_bufs * sizeof(struct niobuf_local));
1030         if (rnb)
1031                 OBD_FREE(rnb, oa_bufs * sizeof(struct niobuf_remote));
1032         RETURN(ret);
1033 }