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_shift_64(-OBD_STATFS_CACHE_SECONDS))) {
 157 restat:
 158                 rc = fsfilt_statfs(obd, obd->u.obt.obt_sb,
 159                                    cfs_time_shift_64(OBD_STATFS_CACHE_SECONDS));
 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 aggressive GFP_HIGHUSER flags from non-local clients to be able to
 272  * generate more memory pressure.
 273  *
 274  * See Bug 19529 and Bug 19917 for details.
 275  */
 276 static struct page *filter_get_page(struct obd_device *obd,
 277                                     struct inode *inode,
 278                                     obd_off offset,
 279                                     int localreq)
 280 {
 281         struct page *page;
 282
 283         page = find_or_create_page(inode->i_mapping, offset >> CFS_PAGE_SHIFT,
 284                                    (localreq ? (GFP_NOFS | __GFP_HIGHMEM)
 285                                              : GFP_HIGHUSER));
 286         if (unlikely(page == NULL))
 287                 lprocfs_counter_add(obd->obd_stats, LPROC_FILTER_NO_PAGE, 1);
 288
 289         return page;
 290 }
 291
 292 /*
 293  * the routine initializes array of local_niobuf from remote_niobuf
 294  */
 295 static int filter_map_remote_to_local(int objcount, struct obd_ioobj *obj,
 296                                       struct niobuf_remote *nb,
 297                                       int *nrpages, struct niobuf_local *res)
 298 {
 299         struct niobuf_remote *rnb;
 300         struct niobuf_local *lnb;
 301         int i, max;
 302         ENTRY;
 303
 304         /* we don't support multiobject RPC yet
 305          * ost_brw_read() and ost_brw_write() check this */
 306         LASSERT(objcount == 1);
 307
 308         max = *nrpages;
 309         *nrpages = 0;
 310         for (i = 0, rnb = nb, lnb = res; i < obj->ioo_bufcnt; i++, rnb++) {
 311                 obd_off offset = rnb->offset;
 312                 unsigned int len = rnb->len;
 313
 314                 while (len > 0) {
 315                         int poff = offset & (CFS_PAGE_SIZE - 1);
 316                         int plen = CFS_PAGE_SIZE - poff;
 317
 318                         if (*nrpages >= max) {
 319                                 CERROR("small array of local bufs: %d\n", max);
 320                                 RETURN(-EINVAL);
 321                         }
 322
 323                         if (plen > len)
 324                                 plen = len;
 325                         lnb->offset = offset;
 326                         lnb->len = plen;
 327                         lnb->flags = rnb->flags;
 328                         lnb->page = NULL;
 329                         lnb->rc = 0;
 330                         lnb->lnb_grant_used = 0;
 331
 332                         LASSERTF(plen <= len, "plen %u, len %u\n", plen, len);
 333                         offset += plen;
 334                         len -= plen;
 335                         lnb++;
 336                         (*nrpages)++;
 337                 }
 338         }
 339         RETURN(0);
 340 }
 341
 342 /*
 343  * the invalidate above doesn't work during read because lnet pins pages.
 344  * The truncate is used here instead to drop pages from cache
 345  */
 346 void filter_release_cache(struct obd_device *obd, struct obd_ioobj *obj,
 347                           struct niobuf_remote *rnb, struct inode *inode)
 348 {
 349         int i;
 350
 351         LASSERT(inode != NULL);
 352         for (i = 0; i < obj->ioo_bufcnt; i++, rnb++) {
 353 #ifdef HAVE_TRUNCATE_RANGE
 354                 /* remove pages in which range is fit */
 355                 truncate_inode_pages_range(inode->i_mapping,
 356                                            rnb->offset & CFS_PAGE_MASK,
 357                                            (rnb->offset + rnb->len - 1) |
 358                                            ~CFS_PAGE_MASK);
 359 #else
 360                 /* use invalidate for old kernels */
 361                 invalidate_mapping_pages(inode->i_mapping,
 362                                          rnb->offset >> CFS_PAGE_SHIFT,
 363                                          (rnb->offset + rnb->len) >>
 364                                          CFS_PAGE_SHIFT);
 365 #endif
 366         }
 367 }
 368
 369 static int filter_preprw_read(int cmd, struct obd_export *exp, struct obdo *oa,
 370                               int objcount, struct obd_ioobj *obj,
 371                               struct niobuf_remote *nb,
 372                               int *npages, struct niobuf_local *res,
 373                               struct obd_trans_info *oti,
 374                               struct lustre_capa *capa)
 375 {
 376         struct obd_device *obd = exp->exp_obd;
 377         struct timeval start, end;
 378         struct lvfs_run_ctxt saved;
 379         struct niobuf_local *lnb;
 380         struct dentry *dentry = NULL;
 381         struct inode *inode = NULL;
 382         void *iobuf = NULL;
 383         int rc = 0, i, tot_bytes = 0;
 384         unsigned long now = jiffies;
 385         long timediff;
 386         loff_t isize;
 387         ENTRY;
 388
 389         /* We are currently not supporting multi-obj BRW_READ RPCS at all.
 390          * When we do this function's dentry cleanup will need to be fixed.
 391          * These values are verified in ost_brw_write() from the wire. */
 392         LASSERTF(objcount == 1, "%d\n", objcount);
 393         LASSERTF(obj->ioo_bufcnt > 0, "%d\n", obj->ioo_bufcnt);
 394
 395         rc = filter_auth_capa(exp, NULL, oa->o_seq, capa,
 396                               CAPA_OPC_OSS_READ);
 397         if (rc)
 398                 RETURN(rc);
 399
 400         if (oa && oa->o_valid & OBD_MD_FLGRANT) {
 401                 cfs_spin_lock(&obd->obd_osfs_lock);
 402                 filter_grant_incoming(exp, oa);
 403
 404                 if (!(oa->o_flags & OBD_FL_SHRINK_GRANT))
 405                         oa->o_grant = 0;
 406                 cfs_spin_unlock(&obd->obd_osfs_lock);
 407         }
 408
 409         iobuf = filter_iobuf_get(&obd->u.filter, oti);
 410         if (IS_ERR(iobuf))
 411                 RETURN(PTR_ERR(iobuf));
 412
 413         push_ctxt(&saved, &obd->obd_lvfs_ctxt, NULL);
 414         dentry = filter_oa2dentry(obd, &oa->o_oi);
 415         if (IS_ERR(dentry)) {
 416                 rc = PTR_ERR(dentry);
 417                 dentry = NULL;
 418                 GOTO(cleanup, rc);
 419         }
 420
 421         inode = dentry->d_inode;
 422         isize = i_size_read(inode);
 423
 424         obdo_to_inode(inode, oa, OBD_MD_FLATIME);
 425
 426         rc = filter_map_remote_to_local(objcount, obj, nb, npages, res);
 427         if (rc)
 428                 GOTO(cleanup, rc);
 429
 430         fsfilt_check_slow(obd, now, "preprw_read setup");
 431
 432         /* find pages for all segments, fill array with them */
 433         cfs_gettimeofday(&start);
 434         for (i = 0, lnb = res; i < *npages; i++, lnb++) {
 435
 436                 lnb->dentry = dentry;
 437
 438                 if (isize <= lnb->offset)
 439                         /* If there's no more data, abort early.  lnb->rc == 0,
 440                          * so it's easy to detect later. */
 441                         break;
 442
 443                 lnb->page = filter_get_page(obd, inode, lnb->offset, 0);
 444                 if (lnb->page == NULL)
 445                         GOTO(cleanup, rc = -ENOMEM);
 446
 447                 lprocfs_counter_add(obd->obd_stats, LPROC_FILTER_CACHE_ACCESS, 1);
 448
 449                 if (isize < lnb->offset + lnb->len - 1)
 450                         lnb->rc = isize - lnb->offset;
 451                 else
 452                         lnb->rc = lnb->len;
 453
 454                 tot_bytes += lnb->rc;
 455
 456                 if (PageUptodate(lnb->page)) {
 457                         lprocfs_counter_add(obd->obd_stats,
 458                                             LPROC_FILTER_CACHE_HIT, 1);
 459                         continue;
 460                 }
 461
 462                 lprocfs_counter_add(obd->obd_stats, LPROC_FILTER_CACHE_MISS, 1);
 463                 filter_iobuf_add_page(obd, iobuf, inode, lnb->page);
 464         }
 465         cfs_gettimeofday(&end);
 466         timediff = cfs_timeval_sub(&end, &start, NULL);
 467         lprocfs_counter_add(obd->obd_stats, LPROC_FILTER_GET_PAGE, timediff);
 468
 469         if (OBD_FAIL_CHECK(OBD_FAIL_OST_NOMEM))
 470                 GOTO(cleanup, rc = -ENOMEM);
 471
 472         fsfilt_check_slow(obd, now, "start_page_read");
 473
 474         rc = filter_direct_io(OBD_BRW_READ, dentry, iobuf,
 475                               exp, NULL, NULL, NULL);
 476         if (rc)
 477                 GOTO(cleanup, rc);
 478
 479         lprocfs_counter_add(obd->obd_stats, LPROC_FILTER_READ_BYTES, tot_bytes);
 480
 481         if (exp->exp_nid_stats && exp->exp_nid_stats->nid_stats)
 482                 lprocfs_counter_add(exp->exp_nid_stats->nid_stats,
 483                                     LPROC_FILTER_READ_BYTES, tot_bytes);
 484
 485         EXIT;
 486
 487  cleanup:
 488         /* unlock pages to allow access from concurrent OST_READ */
 489         for (i = 0, lnb = res; i < *npages; i++, lnb++) {
 490                 if (lnb->page) {
 491                         LASSERT(PageLocked(lnb->page));
 492                         unlock_page(lnb->page);
 493
 494                         if (rc) {
 495                                 page_cache_release(lnb->page);
 496                                 lnb->page = NULL;
 497                         }
 498                 }
 499         }
 500
 501         if (rc != 0) {
 502                 if (dentry != NULL)
 503                         f_dput(dentry);
 504         }
 505
 506         filter_iobuf_put(&obd->u.filter, iobuf, oti);
 507
 508         pop_ctxt(&saved, &obd->obd_lvfs_ctxt, NULL);
 509         if (rc)
 510                 CERROR("io error %d\n", rc);
 511
 512         return rc;
 513 }
 514
 515 /* When clients have dirtied as much space as they've been granted they
 516  * fall through to sync writes.  These sync writes haven't been expressed
 517  * in grants and need to error with ENOSPC when there isn't room in the
 518  * filesystem for them after grants are taken into account.  However,
 519  * writeback of the dirty data that was already granted space can write
 520  * right on through.
 521  *
 522  * Caller must hold obd_osfs_lock. */
 523 static int filter_grant_check(struct obd_export *exp, struct obdo *oa,
 524                               int objcount, struct fsfilt_objinfo *fso,
 525                               int niocount, struct niobuf_local *lnb,
 526                               obd_size *left, struct inode *inode)
 527 {
 528         struct filter_export_data *fed = &exp->exp_filter_data;
 529         int blocksize = exp->exp_obd->u.obt.obt_sb->s_blocksize;
 530         unsigned long used = 0, ungranted = 0, using;
 531         int i, rc = -ENOSPC, obj, n = 0;
 532
 533         LASSERT_SPIN_LOCKED(&exp->exp_obd->obd_osfs_lock);
 534
 535         for (obj = 0; obj < objcount; obj++) {
 536                 for (i = 0; i < fso[obj].fso_bufcnt; i++, n++) {
 537                         int tmp, bytes;
 538
 539                         /* should match the code in osc_exit_cache */
 540                         bytes = lnb[n].len;
 541                         bytes += lnb[n].offset & (blocksize - 1);
 542                         tmp = (lnb[n].offset + lnb[n].len) & (blocksize - 1);
 543                         if (tmp)
 544                                 bytes += blocksize - tmp;
 545
 546                         if ((lnb[n].flags & OBD_BRW_FROM_GRANT) &&
 547                             (oa->o_valid & OBD_MD_FLGRANT)) {
 548                                 if (fed->fed_grant < used + bytes) {
 549                                         CDEBUG(D_CACHE,
 550                                                "%s: cli %s/%p claims %ld+%d "
 551                                                "GRANT, real grant %lu idx %d\n",
 552                                                exp->exp_obd->obd_name,
 553                                                exp->exp_client_uuid.uuid, exp,
 554                                                used, bytes, fed->fed_grant, n);
 555                                 } else {
 556                                         used += bytes;
 557                                         lnb[n].flags |= OBD_BRW_GRANTED;
 558                                         lnb[n].lnb_grant_used = bytes;
 559                                         CDEBUG(0, "idx %d used=%lu\n", n, used);
 560                                         rc = 0;
 561                                         continue;
 562                                 }
 563                         }
 564                         if (*left > ungranted + bytes) {
 565                                 /* if enough space, pretend it was granted */
 566                                 ungranted += bytes;
 567                                 lnb[n].flags |= OBD_BRW_GRANTED;
 568                                 lnb[n].lnb_grant_used = bytes;
 569                                 CDEBUG(0, "idx %d ungranted=%lu\n",n,ungranted);
 570                                 rc = 0;
 571                                 continue;
 572                         }
 573
 574                         /* We can't check for already-mapped blocks here, as
 575                          * it requires dropping the osfs lock to do the bmap.
 576                          * Instead, we return ENOSPC and in that case we need
 577                          * to go through and verify if all of the blocks not
 578                          * marked BRW_GRANTED are already mapped and we can
 579                          * ignore this error. */
 580                         lnb[n].rc = -ENOSPC;
 581                         lnb[n].flags &= ~OBD_BRW_GRANTED;
 582                         CDEBUG(D_CACHE,"%s: cli %s/%p idx %d no space for %d\n",
 583                                exp->exp_obd->obd_name,
 584                                exp->exp_client_uuid.uuid, exp, n, bytes);
 585                 }
 586         }
 587
 588         /* Now substract what client have used already.  We don't subtract
 589          * this from the tot_granted yet, so that other client's can't grab
 590          * that space before we have actually allocated our blocks.  That
 591          * happens in filter_grant_commit() after the writes are done. */
 592         *left -= ungranted;
 593         fed->fed_grant -= used;
 594         fed->fed_pending += used + ungranted;
 595         exp->exp_obd->u.filter.fo_tot_granted += ungranted;
 596         exp->exp_obd->u.filter.fo_tot_pending += used + ungranted;
 597
 598         CDEBUG(D_CACHE,
 599                "%s: cli %s/%p used: %lu ungranted: %lu grant: %lu dirty: %lu\n",
 600                exp->exp_obd->obd_name, exp->exp_client_uuid.uuid, exp, used,
 601                ungranted, fed->fed_grant, fed->fed_dirty);
 602
 603         /* Rough calc in case we don't refresh cached statfs data */
 604         using = (used + ungranted + 1 ) >>
 605                 exp->exp_obd->u.obt.obt_sb->s_blocksize_bits;
 606         if (exp->exp_obd->obd_osfs.os_bavail > using)
 607                 exp->exp_obd->obd_osfs.os_bavail -= using;
 608         else
 609                 exp->exp_obd->obd_osfs.os_bavail = 0;
 610
 611         if (fed->fed_dirty < used) {
 612                 CERROR("%s: cli %s/%p claims used %lu > fed_dirty %lu\n",
 613                        exp->exp_obd->obd_name, exp->exp_client_uuid.uuid, exp,
 614                        used, fed->fed_dirty);
 615                 used = fed->fed_dirty;
 616         }
 617         exp->exp_obd->u.filter.fo_tot_dirty -= used;
 618         fed->fed_dirty -= used;
 619
 620         if (fed->fed_dirty < 0 || fed->fed_grant < 0 || fed->fed_pending < 0) {
 621                 CERROR("%s: cli %s/%p dirty %ld pend %ld grant %ld\n",
 622                        exp->exp_obd->obd_name, exp->exp_client_uuid.uuid, exp,
 623                        fed->fed_dirty, fed->fed_pending, fed->fed_grant);
 624                 cfs_spin_unlock(&exp->exp_obd->obd_osfs_lock);
 625                 LBUG();
 626         }
 627         return rc;
 628 }
 629
 630 /* If we ever start to support multi-object BRW RPCs, we will need to get locks
 631  * on mulitple inodes.  That isn't all, because there still exists the
 632  * possibility of a truncate starting a new transaction while holding the ext3
 633  * rwsem = write while some writes (which have started their transactions here)
 634  * blocking on the ext3 rwsem = read => lock inversion.
 635  *
 636  * The handling gets very ugly when dealing with locked pages.  It may be easier
 637  * to just get rid of the locked page code (which has problems of its own) and
 638  * either discover we do not need it anymore (i.e. it was a symptom of another
 639  * bug) or ensure we get the page locks in an appropriate order. */
 640 static int filter_preprw_write(int cmd, struct obd_export *exp, struct obdo *oa,
 641                                int objcount, struct obd_ioobj *obj,
 642                                struct niobuf_remote *nb, int *npages,
 643                                struct niobuf_local *res,
 644                                struct obd_trans_info *oti,
 645                                struct lustre_capa *capa)
 646 {
 647         struct obd_device *obd = exp->exp_obd;
 648         struct timeval start, end;
 649         struct lvfs_run_ctxt saved;
 650         struct niobuf_local *lnb = res;
 651         struct fsfilt_objinfo fso;
 652         struct filter_mod_data *fmd;
 653         struct dentry *dentry = NULL;
 654         void *iobuf;
 655         obd_size left;
 656         unsigned long now = jiffies, timediff;
 657         int rc = 0, i, tot_bytes = 0, cleanup_phase = 0, localreq = 0;
 658         ENTRY;
 659         LASSERT(objcount == 1);
 660         LASSERT(obj->ioo_bufcnt > 0);
 661
 662         rc = filter_auth_capa(exp, NULL, oa->o_seq, capa,
 663                               CAPA_OPC_OSS_WRITE);
 664         if (rc)
 665                 RETURN(rc);
 666
 667         if (exp->exp_connection &&
 668             exp->exp_connection->c_peer.nid == exp->exp_connection->c_self)
 669                 localreq = 1;
 670
 671         push_ctxt(&saved, &obd->obd_lvfs_ctxt, NULL);
 672         iobuf = filter_iobuf_get(&obd->u.filter, oti);
 673         if (IS_ERR(iobuf))
 674                 GOTO(cleanup, rc = PTR_ERR(iobuf));
 675         cleanup_phase = 1;
 676
 677         dentry = filter_fid2dentry(obd, NULL, obj->ioo_seq,
 678                                    obj->ioo_id);
 679         if (IS_ERR(dentry))
 680                 GOTO(cleanup, rc = PTR_ERR(dentry));
 681         cleanup_phase = 2;
 682
 683         if (dentry->d_inode == NULL) {
 684                 CERROR("%s: trying to BRW to non-existent file "LPU64"\n",
 685                        obd->obd_name, obj->ioo_id);
 686                 GOTO(cleanup, rc = -ENOENT);
 687         }
 688
 689         if (oa->o_valid & (OBD_MD_FLUID | OBD_MD_FLGID) &&
 690             dentry->d_inode->i_mode & (S_ISUID | S_ISGID)) {
 691                 rc = filter_capa_fixoa(exp, oa, oa->o_seq, capa);
 692                 if (rc)
 693                         GOTO(cleanup, rc);
 694         }
 695
 696         rc = filter_map_remote_to_local(objcount, obj, nb, npages, res);
 697         if (rc)
 698                 GOTO(cleanup, rc);
 699
 700         fsfilt_check_slow(obd, now, "preprw_write setup");
 701
 702         /* Filter truncate first locks i_mutex then partially truncated
 703          * page, filter write code first locks pages then take
 704          * i_mutex.  To avoid a deadlock in case of concurrent
 705          * punch/write requests from one client, filter writes and
 706          * filter truncates are serialized by i_alloc_sem, allowing
 707          * multiple writes or single truncate. */
 708         down_read(&dentry->d_inode->i_alloc_sem);
 709
 710         /* Don't update inode timestamps if this write is older than a
 711          * setattr which modifies the timestamps. b=10150 */
 712         /* XXX when we start having persistent reservations this needs to
 713          * be changed to filter_fmd_get() to create the fmd if it doesn't
 714          * already exist so we can store the reservation handle there. */
 715         fmd = filter_fmd_find(exp, obj->ioo_id, obj->ioo_seq);
 716
 717         LASSERT(oa != NULL);
 718         cfs_spin_lock(&obd->obd_osfs_lock);
 719         filter_grant_incoming(exp, oa);
 720         if (fmd && fmd->fmd_mactime_xid > oti->oti_xid)
 721                 oa->o_valid &= ~(OBD_MD_FLMTIME | OBD_MD_FLCTIME |
 722                                  OBD_MD_FLATIME);
 723         else
 724                 obdo_to_inode(dentry->d_inode, oa, OBD_MD_FLATIME |
 725                               OBD_MD_FLMTIME | OBD_MD_FLCTIME);
 726         cleanup_phase = 3;
 727
 728         left = filter_grant_space_left(exp);
 729
 730         fso.fso_dentry = dentry;
 731         fso.fso_bufcnt = *npages;
 732
 733         rc = filter_grant_check(exp, oa, objcount, &fso, *npages, res,
 734                                 &left, dentry->d_inode);
 735
 736         /* do not zero out oa->o_valid as it is used in filter_commitrw_write()
 737          * for setting UID/GID and fid EA in first write time. */
 738         /* If OBD_FL_SHRINK_GRANT is set, the client just returned us some grant
 739          * so no sense in allocating it some more. We either return the grant
 740          * back to the client if we have plenty of space or we don't return
 741          * anything if we are short. This was decided in filter_grant_incoming*/
 742         if (oa->o_valid & OBD_MD_FLGRANT &&!(oa->o_valid & OBD_FL_SHRINK_GRANT))
 743                 oa->o_grant = filter_grant(exp, oa->o_grant, oa->o_undirty,
 744                                            left, 1);
 745
 746         cfs_spin_unlock(&obd->obd_osfs_lock);
 747         filter_fmd_put(exp, fmd);
 748
 749         OBD_FAIL_TIMEOUT(OBD_FAIL_OST_BRW_PAUSE_BULK2, (obd_timeout + 1) / 4);
 750
 751         if (rc)
 752                 GOTO(cleanup, rc);
 753         cleanup_phase = 4;
 754
 755         cfs_gettimeofday(&start);
 756         for (i = 0, lnb = res; i < *npages; i++, lnb++) {
 757
 758                 /* We still set up for ungranted pages so that granted pages
 759                  * can be written to disk as they were promised, and portals
 760                  * needs to keep the pages all aligned properly. */
 761                 lnb->dentry = dentry;
 762
 763                 lnb->page = filter_get_page(obd, dentry->d_inode, lnb->offset,
 764                                             localreq);
 765                 if (lnb->page == NULL)
 766                         GOTO(cleanup, rc = -ENOMEM);
 767
 768                 /* DLM locking protects us from write and truncate competing
 769                  * for same region, but truncate can leave dirty page in the
 770                  * cache. it's possible the writeout on a such a page is in
 771                  * progress when we access it. it's also possible that during
 772                  * this writeout we put new (partial) data, but then won't
 773                  * be able to proceed in filter_commitrw_write(). thus let's
 774                  * just wait for writeout completion, should be rare enough.
 775                  * -bzzz */
 776                 wait_on_page_writeback(lnb->page);
 777                 BUG_ON(PageWriteback(lnb->page));
 778
 779                 /* If the filter writes a partial page, then has the file
 780                  * extended, the client will read in the whole page.  the
 781                  * filter has to be careful to zero the rest of the partial
 782                  * page on disk.  we do it by hand for partial extending
 783                  * writes, send_bio() is responsible for zeroing pages when
 784                  * asked to read unmapped blocks -- brw_kiovec() does this. */
 785                 if (lnb->len != CFS_PAGE_SIZE) {
 786                         __s64 maxidx;
 787
 788                         maxidx = ((i_size_read(dentry->d_inode) +
 789                                    CFS_PAGE_SIZE - 1) >> CFS_PAGE_SHIFT) - 1;
 790                         if (maxidx >= lnb->page->index) {
 791                                 LL_CDEBUG_PAGE(D_PAGE, lnb->page, "write %u @ "
 792                                                LPU64" flg %x before EOF %llu\n",
 793                                                lnb->len, lnb->offset,lnb->flags,
 794                                                i_size_read(dentry->d_inode));
 795                                 filter_iobuf_add_page(obd, iobuf,
 796                                                       dentry->d_inode,
 797                                                       lnb->page);
 798                         } else {
 799                                 long off;
 800                                 char *p = kmap(lnb->page);
 801
 802                                 off = lnb->offset & ~CFS_PAGE_MASK;
 803                                 if (off)
 804                                         memset(p, 0, off);
 805                                 off = (lnb->offset + lnb->len) & ~CFS_PAGE_MASK;
 806                                 if (off)
 807                                         memset(p + off, 0, CFS_PAGE_SIZE - off);
 808                                 kunmap(lnb->page);
 809                         }
 810                 }
 811                 if (lnb->rc == 0)
 812                         tot_bytes += lnb->len;
 813         }
 814         cfs_gettimeofday(&end);
 815         timediff = cfs_timeval_sub(&end, &start, NULL);
 816         lprocfs_counter_add(obd->obd_stats, LPROC_FILTER_GET_PAGE, timediff);
 817
 818         if (OBD_FAIL_CHECK(OBD_FAIL_OST_NOMEM))
 819                 GOTO(cleanup, rc = -ENOMEM);
 820
 821         /* don't unlock pages to prevent any access */
 822         rc = filter_direct_io(OBD_BRW_READ, dentry, iobuf, exp,
 823                               NULL, NULL, NULL);
 824
 825         fsfilt_check_slow(obd, now, "start_page_write");
 826
 827         lprocfs_counter_add(obd->obd_stats, LPROC_FILTER_WRITE_BYTES,
 828                             tot_bytes);
 829
 830         if (exp->exp_nid_stats && exp->exp_nid_stats->nid_stats)
 831                 lprocfs_counter_add(exp->exp_nid_stats->nid_stats,
 832                                     LPROC_FILTER_WRITE_BYTES, tot_bytes);
 833         EXIT;
 834 cleanup:
 835         switch(cleanup_phase) {
 836         case 4:
 837                 if (rc) {
 838                         for (i = 0, lnb = res; i < *npages; i++, lnb++) {
 839                                 if (lnb->page != NULL) {
 840                                         unlock_page(lnb->page);
 841                                         page_cache_release(lnb->page);
 842                                         lnb->page = NULL;
 843                                 }
 844                         }
 845                 }
 846         case 3:
 847                 if (rc)
 848                         up_read(&dentry->d_inode->i_alloc_sem);
 849
 850                 filter_iobuf_put(&obd->u.filter, iobuf, oti);
 851         case 2:
 852                 pop_ctxt(&saved, &obd->obd_lvfs_ctxt, NULL);
 853                 if (rc)
 854                         f_dput(dentry);
 855                 break;
 856         case 1:
 857                 filter_iobuf_put(&obd->u.filter, iobuf, oti);
 858         case 0:
 859                 cfs_spin_lock(&obd->obd_osfs_lock);
 860                 if (oa)
 861                         filter_grant_incoming(exp, oa);
 862                 cfs_spin_unlock(&obd->obd_osfs_lock);
 863                 pop_ctxt(&saved, &obd->obd_lvfs_ctxt, NULL);
 864                 break;
 865         default:;
 866         }
 867         return rc;
 868 }
 869
 870 int filter_preprw(int cmd, struct obd_export *exp, struct obdo *oa,
 871                   int objcount, struct obd_ioobj *obj,
 872                   struct niobuf_remote *nb, int *npages,
 873                   struct niobuf_local *res, struct obd_trans_info *oti,
 874                   struct lustre_capa *capa)
 875 {
 876         if (cmd == OBD_BRW_WRITE)
 877                 return filter_preprw_write(cmd, exp, oa, objcount, obj,
 878                                            nb, npages, res, oti, capa);
 879         if (cmd == OBD_BRW_READ)
 880                 return filter_preprw_read(cmd, exp, oa, objcount, obj,
 881                                           nb, npages, res, oti, capa);
 882         LBUG();
 883         return -EPROTO;
 884 }
 885
 886 static int filter_commitrw_read(struct obd_export *exp, struct obdo *oa,
 887                                 int objcount, struct obd_ioobj *obj,
 888                                 struct niobuf_remote *rnb,
 889                                 int npages, struct niobuf_local *res,
 890                                 struct obd_trans_info *oti, int rc)
 891 {
 892         struct filter_obd *fo = &exp->exp_obd->u.filter;
 893         struct inode *inode = NULL;
 894         struct ldlm_res_id res_id;
 895         struct ldlm_resource *resource = NULL;
 896         struct ldlm_namespace *ns = exp->exp_obd->obd_namespace;
 897         struct niobuf_local *lnb;
 898         int i;
 899         ENTRY;
 900
 901         osc_build_res_name(obj->ioo_id, obj->ioo_seq, &res_id);
 902         /* If oa != NULL then filter_preprw_read updated the inode atime
 903          * and we should update the lvb so that other glimpses will also
 904          * get the updated value. bug 5972 */
 905         if (oa && ns && ns->ns_lvbo && ns->ns_lvbo->lvbo_update) {
 906                 resource = ldlm_resource_get(ns, NULL, &res_id, LDLM_EXTENT, 0);
 907
 908                 if (resource != NULL) {
 909                         LDLM_RESOURCE_ADDREF(resource);
 910                         ns->ns_lvbo->lvbo_update(resource, NULL, 1);
 911                         LDLM_RESOURCE_DELREF(resource);
 912                         ldlm_resource_putref(resource);
 913                 }
 914         }
 915
 916         if (res->dentry != NULL)
 917                 inode = res->dentry->d_inode;
 918
 919         for (i = 0, lnb = res; i < npages; i++, lnb++) {
 920                 if (lnb->page != NULL) {
 921                         page_cache_release(lnb->page);
 922                         lnb->page = NULL;
 923                 }
 924         }
 925         if (inode && (fo->fo_read_cache == 0 ||
 926                       i_size_read(inode) > fo->fo_readcache_max_filesize))
 927                 filter_release_cache(exp->exp_obd, obj, rnb, inode);
 928
 929         if (res->dentry != NULL)
 930                 f_dput(res->dentry);
 931         RETURN(rc);
 932 }
 933
 934 void filter_grant_commit(struct obd_export *exp, int niocount,
 935                          struct niobuf_local *res)
 936 {
 937         struct filter_obd *filter = &exp->exp_obd->u.filter;
 938         struct niobuf_local *lnb = res;
 939         unsigned long pending = 0;
 940         int i;
 941
 942         cfs_spin_lock(&exp->exp_obd->obd_osfs_lock);
 943         for (i = 0, lnb = res; i < niocount; i++, lnb++)
 944                 pending += lnb->lnb_grant_used;
 945
 946         LASSERTF(exp->exp_filter_data.fed_pending >= pending,
 947                  "%s: cli %s/%p fed_pending: %lu grant_used: %lu\n",
 948                  exp->exp_obd->obd_name, exp->exp_client_uuid.uuid, exp,
 949                  exp->exp_filter_data.fed_pending, pending);
 950         exp->exp_filter_data.fed_pending -= pending;
 951         LASSERTF(filter->fo_tot_granted >= pending,
 952                  "%s: cli %s/%p tot_granted: "LPU64" grant_used: %lu\n",
 953                  exp->exp_obd->obd_name, exp->exp_client_uuid.uuid, exp,
 954                  exp->exp_obd->u.filter.fo_tot_granted, pending);
 955         filter->fo_tot_granted -= pending;
 956         LASSERTF(filter->fo_tot_pending >= pending,
 957                  "%s: cli %s/%p tot_pending: "LPU64" grant_used: %lu\n",
 958                  exp->exp_obd->obd_name, exp->exp_client_uuid.uuid, exp,
 959                  filter->fo_tot_pending, pending);
 960         filter->fo_tot_pending -= pending;
 961
 962         cfs_spin_unlock(&exp->exp_obd->obd_osfs_lock);
 963 }
 964
 965 int filter_commitrw(int cmd, struct obd_export *exp, struct obdo *oa,
 966                     int objcount, struct obd_ioobj *obj,
 967                     struct niobuf_remote *nb, int npages,
 968                     struct niobuf_local *res, struct obd_trans_info *oti,
 969                     int rc)
 970 {
 971         if (cmd == OBD_BRW_WRITE)
 972                 return filter_commitrw_write(exp, oa, objcount, obj,
 973                                              nb, npages, res, oti, rc);
 974         if (cmd == OBD_BRW_READ)
 975                 return filter_commitrw_read(exp, oa, objcount, obj,
 976                                             nb, npages, res, oti, rc);
 977         LBUG();
 978         return -EPROTO;
 979 }
 980
 981 int filter_brw(int cmd, struct obd_export *exp, struct obd_info *oinfo,
 982                obd_count oa_bufs, struct brw_page *pga,
 983                struct obd_trans_info *oti)
 984 {
 985         struct obd_ioobj ioo;
 986         struct niobuf_local *lnb;
 987         struct niobuf_remote *rnb;
 988         obd_count i;
 989         int ret = 0, npages;
 990         ENTRY;
 991
 992         OBD_ALLOC(lnb, oa_bufs * sizeof(struct niobuf_local));
 993         OBD_ALLOC(rnb, oa_bufs * sizeof(struct niobuf_remote));
 994
 995         if (lnb == NULL || rnb == NULL)
 996                 GOTO(out, ret = -ENOMEM);
 997
 998         for (i = 0; i < oa_bufs; i++) {
 999                 lnb[i].page = pga[i].pg;
1000                 rnb[i].offset = pga[i].off;
1001                 rnb[i].len = pga[i].count;
1002         }
1003
1004         obdo_to_ioobj(oinfo->oi_oa, &ioo);
1005         ioo.ioo_bufcnt = oa_bufs;
1006
1007         npages = oa_bufs;
1008         ret = filter_preprw(cmd, exp, oinfo->oi_oa, 1, &ioo,
1009                             rnb, &npages, lnb, oti, oinfo_capa(oinfo));
1010         if (ret != 0)
1011                 GOTO(out, ret);
1012         LASSERTF(oa_bufs == npages, "%u != %u\n", oa_bufs, npages);
1013
1014         ret = filter_commitrw(cmd, exp, oinfo->oi_oa, 1, &ioo, rnb,
1015                               npages, lnb, oti, ret);
1016
1017 out:
1018         if (lnb)
1019                 OBD_FREE(lnb, oa_bufs * sizeof(struct niobuf_local));
1020         if (rnb)
1021                 OBD_FREE(rnb, oa_bufs * sizeof(struct niobuf_remote));
1022         RETURN(ret);
1023 }