lustre/obdfilter/filter_io.c

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  * GPL HEADER START
   5  *
   6  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 only,
  10  * as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License version 2 for more details (a copy is included
  16  * in the LICENSE file that accompanied this code).
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * version 2 along with this program; If not, see
  20  * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
  21  *
  22  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  23  * CA 95054 USA or visit www.sun.com if you need additional information or
  24  * have any questions.
  25  *
  26  * GPL HEADER END
  27  */
  28 /*
  29  * Copyright  2008 Sun Microsystems, Inc. All rights reserved
  30  * Use is subject to license terms.
  31  */
  32 /*
  33  * This file is part of Lustre, http://www.lustre.org/
  34  * Lustre is a trademark of Sun Microsystems, Inc.
  35  *
  36  * lustre/obdfilter/filter_io.c
  37  *
  38  * Author: Peter Braam <braam@clusterfs.com>
  39  * Author: Andreas Dilger <adilger@clusterfs.com>
  40  * Author: Phil Schwan <phil@clusterfs.com>
  41  */
  42
  43 #define DEBUG_SUBSYSTEM S_FILTER
  44
  45 #ifndef AUTOCONF_INCLUDED
  46 #include <linux/config.h>
  47 #endif
  48 #include <linux/module.h>
  49 #include <linux/pagemap.h> // XXX kill me soon
  50 #include <linux/version.h>
  51
  52 #include <obd_class.h>
  53 #include <obd_ost.h>
  54 #include <lustre_fsfilt.h>
  55 #include "filter_internal.h"
  56
  57 int *obdfilter_created_scratchpad;
  58
  59 /* Grab the dirty and seen grant announcements from the incoming obdo.
  60  * We will later calculate the clients new grant and return it.
  61  * Caller must hold osfs lock */
  62 void filter_grant_incoming(struct obd_export *exp, struct obdo *oa)
  63 {
  64         struct filter_export_data *fed;
  65         struct obd_device *obd = exp->exp_obd;
  66         ENTRY;
  67
  68         LASSERT_SPIN_LOCKED(&obd->obd_osfs_lock);
  69
  70         if ((oa->o_valid & (OBD_MD_FLBLOCKS|OBD_MD_FLGRANT)) !=
  71                                         (OBD_MD_FLBLOCKS|OBD_MD_FLGRANT)) {
  72                 oa->o_valid &= ~OBD_MD_FLGRANT;
  73                 EXIT;
  74                 return;
  75         }
  76
  77         fed = &exp->exp_filter_data;
  78
  79         /* Add some margin, since there is a small race if other RPCs arrive
  80          * out-or-order and have already consumed some grant.  We want to
  81          * leave this here in case there is a large error in accounting. */
  82         CDEBUG(D_CACHE,
  83                "%s: cli %s/%p reports grant: "LPU64" dropped: %u, local: %lu\n",
  84                obd->obd_name, exp->exp_client_uuid.uuid, exp, oa->o_grant,
  85                oa->o_dropped, fed->fed_grant);
  86
  87         /* Update our accounting now so that statfs takes it into account.
  88          * Note that fed_dirty is only approximate and can become incorrect
  89          * if RPCs arrive out-of-order.  No important calculations depend
  90          * on fed_dirty however, but we must check sanity to not assert. */
  91         if ((long long)oa->o_dirty < 0)
  92                 oa->o_dirty = 0;
  93         else if (oa->o_dirty > fed->fed_grant + 4 * FILTER_GRANT_CHUNK)
  94                 oa->o_dirty = fed->fed_grant + 4 * FILTER_GRANT_CHUNK;
  95         obd->u.filter.fo_tot_dirty += oa->o_dirty - fed->fed_dirty;
  96         if (fed->fed_grant < oa->o_dropped) {
  97                 CDEBUG(D_CACHE,"%s: cli %s/%p reports %u dropped > grant %lu\n",
  98                        obd->obd_name, exp->exp_client_uuid.uuid, exp,
  99                        oa->o_dropped, fed->fed_grant);
 100                 oa->o_dropped = 0;
 101         }
 102         if (obd->u.filter.fo_tot_granted < oa->o_dropped) {
 103                 CERROR("%s: cli %s/%p reports %u dropped > tot_grant "LPU64"\n",
 104                        obd->obd_name, exp->exp_client_uuid.uuid, exp,
 105                        oa->o_dropped, obd->u.filter.fo_tot_granted);
 106                 oa->o_dropped = 0;
 107         }
 108         obd->u.filter.fo_tot_granted -= oa->o_dropped;
 109         fed->fed_grant -= oa->o_dropped;
 110         fed->fed_dirty = oa->o_dirty;
 111
 112         if (oa->o_flags & OBD_FL_SHRINK_GRANT) {
 113                 obd_size left_space = filter_grant_space_left(exp);
 114                 struct filter_obd *filter = &exp->exp_obd->u.filter;
 115
 116                 /*Only if left_space < fo_tot_clients * 32M,
 117                  *then the grant space could be shrinked */
 118                 if (left_space < filter->fo_tot_granted_clients *
 119                                  FILTER_GRANT_SHRINK_LIMIT) {
 120                         fed->fed_grant -= oa->o_grant;
 121                         filter->fo_tot_granted -= oa->o_grant;
 122                         CDEBUG(D_CACHE, "%s: cli %s/%p shrink "LPU64
 123                                "fed_grant %ld total "LPU64"\n",
 124                                obd->obd_name, exp->exp_client_uuid.uuid,
 125                                exp, oa->o_grant, fed->fed_grant,
 126                                filter->fo_tot_granted);
 127                         oa->o_grant = 0;
 128                 }
 129         }
 130
 131         if (fed->fed_dirty < 0 || fed->fed_grant < 0 || fed->fed_pending < 0) {
 132                 CERROR("%s: cli %s/%p dirty %ld pend %ld grant %ld\n",
 133                        obd->obd_name, exp->exp_client_uuid.uuid, exp,
 134                        fed->fed_dirty, fed->fed_pending, fed->fed_grant);
 135                 spin_unlock(&obd->obd_osfs_lock);
 136                 LBUG();
 137         }
 138         EXIT;
 139 }
 140
 141 /* Figure out how much space is available between what we've granted
 142  * and what remains in the filesystem.  Compensate for ext3 indirect
 143  * block overhead when computing how much free space is left ungranted.
 144  *
 145  * Caller must hold obd_osfs_lock. */
 146 obd_size filter_grant_space_left(struct obd_export *exp)
 147 {
 148         struct obd_device *obd = exp->exp_obd;
 149         int blockbits = obd->u.obt.obt_sb->s_blocksize_bits;
 150         obd_size tot_granted = obd->u.filter.fo_tot_granted, avail, left = 0;
 151         int rc, statfs_done = 0;
 152
 153         LASSERT_SPIN_LOCKED(&obd->obd_osfs_lock);
 154
 155         if (cfs_time_before_64(obd->obd_osfs_age, cfs_time_current_64() - HZ)) {
 156 restat:
 157                 rc = fsfilt_statfs(obd, obd->u.obt.obt_sb,
 158                                    cfs_time_current_64() + HZ);
 159                 if (rc) /* N.B. statfs can't really fail */
 160                         RETURN(0);
 161                 statfs_done = 1;
 162         }
 163
 164         avail = obd->obd_osfs.os_bavail;
 165         left = avail - (avail >> (blockbits - 3)); /* (d)indirect */
 166         if (left > GRANT_FOR_LLOG(obd)) {
 167                 left = (left - GRANT_FOR_LLOG(obd)) << blockbits;
 168         } else {
 169                 left = 0 /* << blockbits */;
 170         }
 171
 172         if (!statfs_done && left < 32 * FILTER_GRANT_CHUNK + tot_granted) {
 173                 CDEBUG(D_CACHE, "fs has no space left and statfs too old\n");
 174                 goto restat;
 175         }
 176
 177         if (left >= tot_granted) {
 178                 left -= tot_granted;
 179         } else {
 180                 if (left < tot_granted - obd->u.filter.fo_tot_pending) {
 181                         CERROR("%s: cli %s/%p grant "LPU64" > available "
 182                                LPU64" and pending "LPU64"\n", obd->obd_name,
 183                                exp->exp_client_uuid.uuid, exp, tot_granted,
 184                                left, obd->u.filter.fo_tot_pending);
 185                 }
 186                 left = 0;
 187         }
 188
 189         CDEBUG(D_CACHE, "%s: cli %s/%p free: "LPU64" avail: "LPU64" grant "LPU64
 190                " left: "LPU64" pending: "LPU64"\n", obd->obd_name,
 191                exp->exp_client_uuid.uuid, exp,
 192                obd->obd_osfs.os_bfree << blockbits, avail << blockbits,
 193                tot_granted, left, obd->u.filter.fo_tot_pending);
 194
 195         return left;
 196 }
 197
 198 /* Calculate how much grant space to allocate to this client, based on how
 199  * much space is currently free and how much of that is already granted.
 200  *
 201  * Caller must hold obd_osfs_lock. */
 202 long filter_grant(struct obd_export *exp, obd_size current_grant,
 203                   obd_size want, obd_size fs_space_left)
 204 {
 205         struct obd_device *obd = exp->exp_obd;
 206         struct filter_export_data *fed = &exp->exp_filter_data;
 207         int blockbits = obd->u.obt.obt_sb->s_blocksize_bits;
 208         __u64 grant = 0;
 209
 210         LASSERT_SPIN_LOCKED(&obd->obd_osfs_lock);
 211
 212         /* Grant some fraction of the client's requested grant space so that
 213          * they are not always waiting for write credits (not all of it to
 214          * avoid overgranting in face of multiple RPCs in flight).  This
 215          * essentially will be able to control the OSC_MAX_RIF for a client.
 216          *
 217          * If we do have a large disparity between what the client thinks it
 218          * has and what we think it has, don't grant very much and let the
 219          * client consume its grant first.  Either it just has lots of RPCs
 220          * in flight, or it was evicted and its grants will soon be used up. */
 221         if (want > 0x7fffffff) {
 222                 CERROR("%s: client %s/%p requesting > 2GB grant "LPU64"\n",
 223                        obd->obd_name, exp->exp_client_uuid.uuid, exp, want);
 224         } else if (current_grant < want &&
 225                    current_grant < fed->fed_grant + FILTER_GRANT_CHUNK) {
 226                 grant = min((want >> blockbits),
 227                             (fs_space_left >> blockbits) / 8);
 228                 grant <<= blockbits;
 229
 230                 if (grant) {
 231                         /* Allow >FILTER_GRANT_CHUNK size when clients
 232                          * reconnect due to a server reboot.
 233                          */
 234                         if ((grant > FILTER_GRANT_CHUNK) &&
 235                             (!obd->obd_recovering))
 236                                 grant = FILTER_GRANT_CHUNK;
 237
 238                         obd->u.filter.fo_tot_granted += grant;
 239                         fed->fed_grant += grant;
 240                         if (fed->fed_grant < 0) {
 241                                 CERROR("%s: cli %s/%p grant %ld want "LPU64
 242                                        "current"LPU64"\n",
 243                                        obd->obd_name, exp->exp_client_uuid.uuid,
 244                                        exp, fed->fed_grant, want,current_grant);
 245                                 spin_unlock(&obd->obd_osfs_lock);
 246                                 LBUG();
 247                         }
 248                 }
 249         }
 250
 251         CDEBUG(D_CACHE,
 252                "%s: cli %s/%p wants: "LPU64" current grant "LPU64
 253                " granting: "LPU64"\n", obd->obd_name, exp->exp_client_uuid.uuid,
 254                exp, want, current_grant, grant);
 255         CDEBUG(D_CACHE,
 256                "%s: cli %s/%p tot cached:"LPU64" granted:"LPU64
 257                " num_exports: %d\n", obd->obd_name, exp->exp_client_uuid.uuid,
 258                exp, obd->u.filter.fo_tot_dirty,
 259                obd->u.filter.fo_tot_granted, obd->obd_num_exports);
 260
 261         return grant;
 262 }
 263
 264 /*
 265  * the routine is used to request pages from pagecache
 266  *
 267  * use GFP_NOFS not allowing to enter FS as the client can run on this node
 268  * and we might end waiting on a page he sent in the request we're serving.
 269  *
 270  * use __GFP_HIGHMEM so that the pages can use all of the available memory
 271  * on 32-bit machines
 272  */
 273 static struct page *filter_get_page(struct obd_device *obd,
 274                                     struct inode *inode,
 275                                     obd_off offset)
 276 {
 277         struct page *page;
 278
 279         page = find_or_create_page(inode->i_mapping, offset >> CFS_PAGE_SHIFT,
 280                                    GFP_NOFS | __GFP_HIGHMEM);
 281         if (unlikely(page == NULL))
 282                 lprocfs_counter_add(obd->obd_stats, LPROC_FILTER_NO_PAGE, 1);
 283
 284         return page;
 285 }
 286
 287 /*
 288  * the routine initializes array of local_niobuf from remote_niobuf
 289  */
 290 static int filter_map_remote_to_local(int objcount, struct obd_ioobj *obj,
 291                                       struct niobuf_remote *nb,
 292                                       int *nrpages, struct niobuf_local *res)
 293 {
 294         struct niobuf_remote *rnb;
 295         struct niobuf_local *lnb;
 296         int i, max;
 297         ENTRY;
 298
 299         /* we don't support multiobject RPC yet
 300          * ost_brw_read() and ost_brw_write() check this */
 301         LASSERT(objcount == 1);
 302
 303         max = *nrpages;
 304         *nrpages = 0;
 305         for (i = 0, rnb = nb, lnb = res; i < obj->ioo_bufcnt; i++, rnb++) {
 306                 obd_off offset = rnb->offset;
 307                 unsigned int len = rnb->len;
 308
 309                 while (len > 0) {
 310                         int poff = offset & (CFS_PAGE_SIZE - 1);
 311                         int plen = CFS_PAGE_SIZE - poff;
 312
 313                         if (*nrpages >= max) {
 314                                 CERROR("small array of local bufs: %d\n", max);
 315                                 RETURN(-EINVAL);
 316                         }
 317
 318                         if (plen > len)
 319                                 plen = len;
 320                         lnb->offset = offset;
 321                         lnb->len = plen;
 322                         lnb->flags = rnb->flags;
 323                         lnb->page = NULL;
 324                         lnb->rc = 0;
 325                         lnb->lnb_grant_used = 0;
 326
 327                         LASSERTF(plen <= len, "plen %u, len %u\n", plen, len);
 328                         offset += plen;
 329                         len -= plen;
 330                         lnb++;
 331                         (*nrpages)++;
 332                 }
 333         }
 334         RETURN(0);
 335 }
 336
 337 /*
 338  * the function is used to free all pages used for request
 339  * just to mimic cacheless OSS which don't occupy much memory
 340  */
 341 void filter_invalidate_cache(struct obd_device *obd, struct obd_ioobj *obj,
 342                              struct niobuf_remote *nb, struct inode *inode)
 343 {
 344         struct niobuf_remote *rnb;
 345         int i;
 346
 347         LASSERT(inode != NULL);
 348
 349         for (i = 0, rnb = nb; i < obj->ioo_bufcnt; i++, rnb++) {
 350                 obd_off start;
 351                 obd_off end;
 352
 353                 start = rnb->offset >> CFS_PAGE_SHIFT;
 354                 end = (rnb->offset + rnb->len) >> CFS_PAGE_SHIFT;
 355                 invalidate_mapping_pages(inode->i_mapping, start, end);
 356                 /* just to avoid warnings */
 357                 start = 0;
 358                 end = 0;
 359         }
 360 }
 361
 362 static int filter_preprw_read(int cmd, struct obd_export *exp, struct obdo *oa,
 363                               int objcount, struct obd_ioobj *obj,
 364                               struct niobuf_remote *nb,
 365                               int *npages, struct niobuf_local *res,
 366                               struct obd_trans_info *oti,
 367                               struct lustre_capa *capa)
 368 {
 369         struct obd_device *obd = exp->exp_obd;
 370         struct timeval start, end;
 371         struct lvfs_run_ctxt saved;
 372         struct niobuf_local *lnb;
 373         struct dentry *dentry = NULL;
 374         struct inode *inode = NULL;
 375         void *iobuf = NULL;
 376         int rc = 0, i, tot_bytes = 0;
 377         unsigned long now = jiffies;
 378         long timediff;
 379         ENTRY;
 380
 381         /* We are currently not supporting multi-obj BRW_READ RPCS at all.
 382          * When we do this function's dentry cleanup will need to be fixed.
 383          * These values are verified in ost_brw_write() from the wire. */
 384         LASSERTF(objcount == 1, "%d\n", objcount);
 385         LASSERTF(obj->ioo_bufcnt > 0, "%d\n", obj->ioo_bufcnt);
 386
 387         rc = filter_auth_capa(exp, NULL, obdo_mdsno(oa), capa,
 388                               CAPA_OPC_OSS_READ);
 389         if (rc)
 390                 RETURN(rc);
 391
 392         if (oa && oa->o_valid & OBD_MD_FLGRANT) {
 393                 spin_lock(&obd->obd_osfs_lock);
 394                 filter_grant_incoming(exp, oa);
 395
 396                 if (!(oa->o_flags & OBD_FL_SHRINK_GRANT))
 397                         oa->o_grant = 0;
 398                 spin_unlock(&obd->obd_osfs_lock);
 399         }
 400
 401         iobuf = filter_iobuf_get(&obd->u.filter, oti);
 402         if (IS_ERR(iobuf))
 403                 RETURN(PTR_ERR(iobuf));
 404
 405         push_ctxt(&saved, &obd->obd_lvfs_ctxt, NULL);
 406         dentry = filter_oa2dentry(obd, oa);
 407         if (IS_ERR(dentry)) {
 408                 rc = PTR_ERR(dentry);
 409                 dentry = NULL;
 410                 GOTO(cleanup, rc);
 411         }
 412
 413         inode = dentry->d_inode;
 414
 415         obdo_to_inode(inode, oa, OBD_MD_FLATIME);
 416
 417         rc = filter_map_remote_to_local(objcount, obj, nb, npages, res);
 418         if (rc)
 419                 GOTO(cleanup, rc);
 420
 421         fsfilt_check_slow(obd, now, "preprw_read setup");
 422
 423         /* find pages for all segments, fill array with them */
 424         do_gettimeofday(&start);
 425         for (i = 0, lnb = res; i < *npages; i++, lnb++) {
 426
 427                 lnb->dentry = dentry;
 428
 429                 if (i_size_read(inode) <= lnb->offset)
 430                         /* If there's no more data, abort early.  lnb->rc == 0,
 431                          * so it's easy to detect later. */
 432                         break;
 433
 434                 lnb->page = filter_get_page(obd, inode, lnb->offset);
 435                 if (lnb->page == NULL)
 436                         GOTO(cleanup, rc = -ENOMEM);
 437
 438                 lprocfs_counter_add(obd->obd_stats, LPROC_FILTER_CACHE_ACCESS, 1);
 439
 440                 if (i_size_read(inode) < lnb->offset + lnb->len - 1)
 441                         lnb->rc = i_size_read(inode) - lnb->offset;
 442                 else
 443                         lnb->rc = lnb->len;
 444
 445                 tot_bytes += lnb->rc;
 446
 447                 if (PageUptodate(lnb->page)) {
 448                         lprocfs_counter_add(obd->obd_stats,
 449                                             LPROC_FILTER_CACHE_HIT, 1);
 450                         continue;
 451                 }
 452
 453                 lprocfs_counter_add(obd->obd_stats, LPROC_FILTER_CACHE_MISS, 1);
 454                 filter_iobuf_add_page(obd, iobuf, inode, lnb->page);
 455         }
 456         do_gettimeofday(&end);
 457         timediff = cfs_timeval_sub(&end, &start, NULL);
 458         lprocfs_counter_add(obd->obd_stats, LPROC_FILTER_GET_PAGE, timediff);
 459
 460         if (OBD_FAIL_CHECK(OBD_FAIL_OST_NOMEM))
 461                 GOTO(cleanup, rc = -ENOMEM);
 462
 463         fsfilt_check_slow(obd, now, "start_page_read");
 464
 465         rc = filter_direct_io(OBD_BRW_READ, dentry, iobuf,
 466                               exp, NULL, NULL, NULL);
 467         if (rc)
 468                 GOTO(cleanup, rc);
 469
 470         lprocfs_counter_add(obd->obd_stats, LPROC_FILTER_READ_BYTES, tot_bytes);
 471
 472         if (exp->exp_nid_stats && exp->exp_nid_stats->nid_stats)
 473                 lprocfs_counter_add(exp->exp_nid_stats->nid_stats,
 474                                     LPROC_FILTER_READ_BYTES, tot_bytes);
 475
 476         EXIT;
 477
 478  cleanup:
 479         /* unlock pages to allow access from concurrent OST_READ */
 480         for (i = 0, lnb = res; i < *npages; i++, lnb++) {
 481                 if (lnb->page) {
 482                         LASSERT(PageLocked(lnb->page));
 483                         unlock_page(lnb->page);
 484
 485                         if (rc) {
 486                                 page_cache_release(lnb->page);
 487                                 lnb->page = NULL;
 488                         }
 489                 }
 490         }
 491
 492         if (rc != 0) {
 493                 if (dentry != NULL)
 494                         f_dput(dentry);
 495         }
 496
 497         filter_iobuf_put(&obd->u.filter, iobuf, oti);
 498
 499         pop_ctxt(&saved, &obd->obd_lvfs_ctxt, NULL);
 500         if (rc)
 501                 CERROR("io error %d\n", rc);
 502
 503         return rc;
 504 }
 505
 506 /* When clients have dirtied as much space as they've been granted they
 507  * fall through to sync writes.  These sync writes haven't been expressed
 508  * in grants and need to error with ENOSPC when there isn't room in the
 509  * filesystem for them after grants are taken into account.  However,
 510  * writeback of the dirty data that was already granted space can write
 511  * right on through.
 512  *
 513  * Caller must hold obd_osfs_lock. */
 514 static int filter_grant_check(struct obd_export *exp, struct obdo *oa,
 515                               int objcount, struct fsfilt_objinfo *fso,
 516                               int niocount, struct niobuf_local *lnb,
 517                               obd_size *left, struct inode *inode)
 518 {
 519         struct filter_export_data *fed = &exp->exp_filter_data;
 520         int blocksize = exp->exp_obd->u.obt.obt_sb->s_blocksize;
 521         unsigned long used = 0, ungranted = 0, using;
 522         int i, rc = -ENOSPC, obj, n = 0;
 523
 524         LASSERT_SPIN_LOCKED(&exp->exp_obd->obd_osfs_lock);
 525
 526         for (obj = 0; obj < objcount; obj++) {
 527                 for (i = 0; i < fso[obj].fso_bufcnt; i++, n++) {
 528                         int tmp, bytes;
 529
 530                         /* should match the code in osc_exit_cache */
 531                         bytes = lnb[n].len;
 532                         bytes += lnb[n].offset & (blocksize - 1);
 533                         tmp = (lnb[n].offset + lnb[n].len) & (blocksize - 1);
 534                         if (tmp)
 535                                 bytes += blocksize - tmp;
 536
 537                         if ((lnb[n].flags & OBD_BRW_FROM_GRANT) &&
 538                             (oa->o_valid & OBD_MD_FLGRANT)) {
 539                                 if (fed->fed_grant < used + bytes) {
 540                                         CDEBUG(D_CACHE,
 541                                                "%s: cli %s/%p claims %ld+%d "
 542                                                "GRANT, real grant %lu idx %d\n",
 543                                                exp->exp_obd->obd_name,
 544                                                exp->exp_client_uuid.uuid, exp,
 545                                                used, bytes, fed->fed_grant, n);
 546                                 } else {
 547                                         used += bytes;
 548                                         lnb[n].flags |= OBD_BRW_GRANTED;
 549                                         lnb[n].lnb_grant_used = bytes;
 550                                         CDEBUG(0, "idx %d used=%lu\n", n, used);
 551                                         rc = 0;
 552                                         continue;
 553                                 }
 554                         }
 555                         if (*left > ungranted + bytes) {
 556                                 /* if enough space, pretend it was granted */
 557                                 ungranted += bytes;
 558                                 lnb[n].flags |= OBD_BRW_GRANTED;
 559                                 lnb[n].lnb_grant_used = bytes;
 560                                 CDEBUG(0, "idx %d ungranted=%lu\n",n,ungranted);
 561                                 rc = 0;
 562                                 continue;
 563                         }
 564
 565                         /* We can't check for already-mapped blocks here, as
 566                          * it requires dropping the osfs lock to do the bmap.
 567                          * Instead, we return ENOSPC and in that case we need
 568                          * to go through and verify if all of the blocks not
 569                          * marked BRW_GRANTED are already mapped and we can
 570                          * ignore this error. */
 571                         lnb[n].rc = -ENOSPC;
 572                         lnb[n].flags &= ~OBD_BRW_GRANTED;
 573                         CDEBUG(D_CACHE,"%s: cli %s/%p idx %d no space for %d\n",
 574                                exp->exp_obd->obd_name,
 575                                exp->exp_client_uuid.uuid, exp, n, bytes);
 576                 }
 577         }
 578
 579         /* Now substract what client have used already.  We don't subtract
 580          * this from the tot_granted yet, so that other client's can't grab
 581          * that space before we have actually allocated our blocks.  That
 582          * happens in filter_grant_commit() after the writes are done. */
 583         *left -= ungranted;
 584         fed->fed_grant -= used;
 585         fed->fed_pending += used + ungranted;
 586         exp->exp_obd->u.filter.fo_tot_granted += ungranted;
 587         exp->exp_obd->u.filter.fo_tot_pending += used + ungranted;
 588
 589         CDEBUG(D_CACHE,
 590                "%s: cli %s/%p used: %lu ungranted: %lu grant: %lu dirty: %lu\n",
 591                exp->exp_obd->obd_name, exp->exp_client_uuid.uuid, exp, used,
 592                ungranted, fed->fed_grant, fed->fed_dirty);
 593
 594         /* Rough calc in case we don't refresh cached statfs data */
 595         using = (used + ungranted + 1 ) >>
 596                 exp->exp_obd->u.obt.obt_sb->s_blocksize_bits;
 597         if (exp->exp_obd->obd_osfs.os_bavail > using)
 598                 exp->exp_obd->obd_osfs.os_bavail -= using;
 599         else
 600                 exp->exp_obd->obd_osfs.os_bavail = 0;
 601
 602         if (fed->fed_dirty < used) {
 603                 CERROR("%s: cli %s/%p claims used %lu > fed_dirty %lu\n",
 604                        exp->exp_obd->obd_name, exp->exp_client_uuid.uuid, exp,
 605                        used, fed->fed_dirty);
 606                 used = fed->fed_dirty;
 607         }
 608         exp->exp_obd->u.filter.fo_tot_dirty -= used;
 609         fed->fed_dirty -= used;
 610
 611         if (fed->fed_dirty < 0 || fed->fed_grant < 0 || fed->fed_pending < 0) {
 612                 CERROR("%s: cli %s/%p dirty %ld pend %ld grant %ld\n",
 613                        exp->exp_obd->obd_name, exp->exp_client_uuid.uuid, exp,
 614                        fed->fed_dirty, fed->fed_pending, fed->fed_grant);
 615                 spin_unlock(&exp->exp_obd->obd_osfs_lock);
 616                 LBUG();
 617         }
 618         return rc;
 619 }
 620
 621 /* If we ever start to support multi-object BRW RPCs, we will need to get locks
 622  * on mulitple inodes.  That isn't all, because there still exists the
 623  * possibility of a truncate starting a new transaction while holding the ext3
 624  * rwsem = write while some writes (which have started their transactions here)
 625  * blocking on the ext3 rwsem = read => lock inversion.
 626  *
 627  * The handling gets very ugly when dealing with locked pages.  It may be easier
 628  * to just get rid of the locked page code (which has problems of its own) and
 629  * either discover we do not need it anymore (i.e. it was a symptom of another
 630  * bug) or ensure we get the page locks in an appropriate order. */
 631 static int filter_preprw_write(int cmd, struct obd_export *exp, struct obdo *oa,
 632                                int objcount, struct obd_ioobj *obj,
 633                                struct niobuf_remote *nb, int *npages,
 634                                struct niobuf_local *res,
 635                                struct obd_trans_info *oti,
 636                                struct lustre_capa *capa)
 637 {
 638         struct obd_device *obd = exp->exp_obd;
 639         struct timeval start, end;
 640         struct lvfs_run_ctxt saved;
 641         struct niobuf_local *lnb = res;
 642         struct fsfilt_objinfo fso;
 643         struct filter_mod_data *fmd;
 644         struct dentry *dentry = NULL;
 645         void *iobuf;
 646         obd_size left;
 647         unsigned long now = jiffies, timediff;
 648         int rc = 0, i, tot_bytes = 0, cleanup_phase = 0;
 649         ENTRY;
 650         LASSERT(objcount == 1);
 651         LASSERT(obj->ioo_bufcnt > 0);
 652
 653         rc = filter_auth_capa(exp, NULL, obdo_mdsno(oa), capa,
 654                               CAPA_OPC_OSS_WRITE);
 655         if (rc)
 656                 RETURN(rc);
 657
 658         push_ctxt(&saved, &obd->obd_lvfs_ctxt, NULL);
 659         iobuf = filter_iobuf_get(&obd->u.filter, oti);
 660         if (IS_ERR(iobuf))
 661                 GOTO(cleanup, rc = PTR_ERR(iobuf));
 662         cleanup_phase = 1;
 663
 664         dentry = filter_fid2dentry(obd, NULL, obj->ioo_gr,
 665                                    obj->ioo_id);
 666         if (IS_ERR(dentry))
 667                 GOTO(cleanup, rc = PTR_ERR(dentry));
 668         cleanup_phase = 2;
 669
 670         if (dentry->d_inode == NULL) {
 671                 CERROR("%s: trying to BRW to non-existent file "LPU64"\n",
 672                        obd->obd_name, obj->ioo_id);
 673                 GOTO(cleanup, rc = -ENOENT);
 674         }
 675
 676         if (oa->o_valid & (OBD_MD_FLUID | OBD_MD_FLGID) &&
 677             dentry->d_inode->i_mode & (S_ISUID | S_ISGID)) {
 678                 rc = filter_capa_fixoa(exp, oa, obdo_mdsno(oa), capa);
 679                 if (rc)
 680                         GOTO(cleanup, rc);
 681         }
 682
 683         rc = filter_map_remote_to_local(objcount, obj, nb, npages, res);
 684         if (rc)
 685                 GOTO(cleanup, rc);
 686
 687         fsfilt_check_slow(obd, now, "preprw_write setup");
 688
 689         /* Don't update inode timestamps if this write is older than a
 690          * setattr which modifies the timestamps. b=10150 */
 691         /* XXX when we start having persistent reservations this needs to
 692          * be changed to filter_fmd_get() to create the fmd if it doesn't
 693          * already exist so we can store the reservation handle there. */
 694         fmd = filter_fmd_find(exp, obj->ioo_id, obj->ioo_gr);
 695
 696         LASSERT(oa != NULL);
 697         spin_lock(&obd->obd_osfs_lock);
 698         filter_grant_incoming(exp, oa);
 699         if (fmd && fmd->fmd_mactime_xid > oti->oti_xid)
 700                 oa->o_valid &= ~(OBD_MD_FLMTIME | OBD_MD_FLCTIME |
 701                                  OBD_MD_FLATIME);
 702         else
 703                 obdo_to_inode(dentry->d_inode, oa, OBD_MD_FLATIME |
 704                               OBD_MD_FLMTIME | OBD_MD_FLCTIME);
 705         cleanup_phase = 3;
 706
 707         left = filter_grant_space_left(exp);
 708
 709         fso.fso_dentry = dentry;
 710         fso.fso_bufcnt = *npages;
 711
 712         rc = filter_grant_check(exp, oa, objcount, &fso, *npages, res,
 713                                 &left, dentry->d_inode);
 714
 715         /* do not zero out oa->o_valid as it is used in filter_commitrw_write()
 716          * for setting UID/GID and fid EA in first write time. */
 717         if (oa->o_valid & OBD_MD_FLGRANT)
 718                 oa->o_grant = filter_grant(exp,oa->o_grant,oa->o_undirty,left);
 719
 720         spin_unlock(&obd->obd_osfs_lock);
 721         filter_fmd_put(exp, fmd);
 722
 723         if (rc)
 724                 GOTO(cleanup, rc);
 725         cleanup_phase = 4;
 726
 727         /* Filter truncate first locks i_mutex then partally truncated
 728          * page, filter write code first locks pages then take
 729          * i_mutex.  To avoid a deadlock in case of concurrent
 730          * punch/write requests from one client, filter writes and
 731          * filter truncates are serialized by i_alloc_sem, allowing
 732          * multiple writes or single truncate. */
 733         down_read(&dentry->d_inode->i_alloc_sem);
 734
 735         do_gettimeofday(&start);
 736         for (i = 0, lnb = res; i < *npages; i++, lnb++) {
 737
 738                 /* We still set up for ungranted pages so that granted pages
 739                  * can be written to disk as they were promised, and portals
 740                  * needs to keep the pages all aligned properly. */
 741                 lnb->dentry = dentry;
 742
 743                 lnb->page = filter_get_page(obd, dentry->d_inode, lnb->offset);
 744                 if (lnb->page == NULL)
 745                         GOTO(cleanup, rc = -ENOMEM);
 746
 747                 /* DLM locking protects us from write and truncate competing
 748                  * for same region, but truncate can leave dirty page in the
 749                  * cache. it's possible the writeout on a such a page is in
 750                  * progress when we access it. it's also possible that during
 751                  * this writeout we put new (partial) data, but then won't
 752                  * be able to proceed in filter_commitrw_write(). thus let's
 753                  * just wait for writeout completion, should be rare enough.
 754                  * -bzzz */
 755                 if (obd->u.filter.fo_writethrough_cache)
 756                         wait_on_page_writeback(lnb->page);
 757                 BUG_ON(PageWriteback(lnb->page));
 758
 759                 /* If the filter writes a partial page, then has the file
 760                  * extended, the client will read in the whole page.  the
 761                  * filter has to be careful to zero the rest of the partial
 762                  * page on disk.  we do it by hand for partial extending
 763                  * writes, send_bio() is responsible for zeroing pages when
 764                  * asked to read unmapped blocks -- brw_kiovec() does this. */
 765                 if (lnb->len != CFS_PAGE_SIZE) {
 766                         __s64 maxidx;
 767
 768                         maxidx = ((i_size_read(dentry->d_inode) +
 769                                    CFS_PAGE_SIZE - 1) >> CFS_PAGE_SHIFT) - 1;
 770                         if (maxidx >= lnb->page->index) {
 771                                 LL_CDEBUG_PAGE(D_PAGE, lnb->page, "write %u @ "
 772                                                LPU64" flg %x before EOF %llu\n",
 773                                                lnb->len, lnb->offset,lnb->flags,
 774                                                i_size_read(dentry->d_inode));
 775                                 filter_iobuf_add_page(obd, iobuf,
 776                                                       dentry->d_inode,
 777                                                       lnb->page);
 778                         } else {
 779                                 long off;
 780                                 char *p = kmap(lnb->page);
 781
 782                                 off = lnb->offset & ~CFS_PAGE_MASK;
 783                                 if (off)
 784                                         memset(p, 0, off);
 785                                 off = (lnb->offset + lnb->len) & ~CFS_PAGE_MASK;
 786                                 if (off)
 787                                         memset(p + off, 0, CFS_PAGE_SIZE - off);
 788                                 kunmap(lnb->page);
 789                         }
 790                 }
 791                 if (lnb->rc == 0)
 792                         tot_bytes += lnb->len;
 793         }
 794         do_gettimeofday(&end);
 795         timediff = cfs_timeval_sub(&end, &start, NULL);
 796         lprocfs_counter_add(obd->obd_stats, LPROC_FILTER_GET_PAGE, timediff);
 797
 798         if (OBD_FAIL_CHECK(OBD_FAIL_OST_NOMEM))
 799                 GOTO(cleanup, rc = -ENOMEM);
 800
 801         /* don't unlock pages to prevent any access */
 802         rc = filter_direct_io(OBD_BRW_READ, dentry, iobuf, exp,
 803                               NULL, NULL, NULL);
 804
 805         fsfilt_check_slow(obd, now, "start_page_write");
 806
 807         if (exp->exp_nid_stats && exp->exp_nid_stats->nid_stats)
 808                 lprocfs_counter_add(exp->exp_nid_stats->nid_stats,
 809                                     LPROC_FILTER_WRITE_BYTES, tot_bytes);
 810         EXIT;
 811 cleanup:
 812         switch(cleanup_phase) {
 813         case 4:
 814                 if (rc) {
 815                         for (i = 0, lnb = res; i < *npages; i++, lnb++) {
 816                                 if (lnb->page != NULL) {
 817                                         unlock_page(lnb->page);
 818                                         page_cache_release(lnb->page);
 819                                         lnb->page = NULL;
 820                                 }
 821                         }
 822                         up_read(&dentry->d_inode->i_alloc_sem);
 823                 }
 824         case 3:
 825                 filter_iobuf_put(&obd->u.filter, iobuf, oti);
 826         case 2:
 827                 pop_ctxt(&saved, &obd->obd_lvfs_ctxt, NULL);
 828                 if (rc)
 829                         f_dput(dentry);
 830                 break;
 831         case 1:
 832                 filter_iobuf_put(&obd->u.filter, iobuf, oti);
 833         case 0:
 834                 spin_lock(&obd->obd_osfs_lock);
 835                 if (oa)
 836                         filter_grant_incoming(exp, oa);
 837                 spin_unlock(&obd->obd_osfs_lock);
 838                 pop_ctxt(&saved, &obd->obd_lvfs_ctxt, NULL);
 839                 break;
 840         default:;
 841         }
 842         return rc;
 843 }
 844
 845 int filter_preprw(int cmd, struct obd_export *exp, struct obdo *oa,
 846                   int objcount, struct obd_ioobj *obj,
 847                   struct niobuf_remote *nb, int *npages,
 848                   struct niobuf_local *res, struct obd_trans_info *oti,
 849                   struct lustre_capa *capa)
 850 {
 851         if (cmd == OBD_BRW_WRITE)
 852                 return filter_preprw_write(cmd, exp, oa, objcount, obj,
 853                                            nb, npages, res, oti, capa);
 854         if (cmd == OBD_BRW_READ)
 855                 return filter_preprw_read(cmd, exp, oa, objcount, obj,
 856                                           nb, npages, res, oti, capa);
 857         LBUG();
 858         return -EPROTO;
 859 }
 860
 861 static int filter_commitrw_read(struct obd_export *exp, struct obdo *oa,
 862                                 int objcount, struct obd_ioobj *obj,
 863                                 struct niobuf_remote *rnb,
 864                                 int npages, struct niobuf_local *res,
 865                                 struct obd_trans_info *oti, int rc)
 866 {
 867         struct filter_obd *fo = &exp->exp_obd->u.filter;
 868         struct inode *inode = NULL;
 869         struct ldlm_res_id res_id;
 870         struct ldlm_resource *resource = NULL;
 871         struct ldlm_namespace *ns = exp->exp_obd->obd_namespace;
 872         struct niobuf_local *lnb;
 873         int i;
 874         ENTRY;
 875
 876         osc_build_res_name(obj->ioo_id, obj->ioo_gr, &res_id);
 877         /* If oa != NULL then filter_preprw_read updated the inode atime
 878          * and we should update the lvb so that other glimpses will also
 879          * get the updated value. bug 5972 */
 880         if (oa && ns && ns->ns_lvbo && ns->ns_lvbo->lvbo_update) {
 881                 resource = ldlm_resource_get(ns, NULL, &res_id, LDLM_EXTENT, 0);
 882
 883                 if (resource != NULL) {
 884                         LDLM_RESOURCE_ADDREF(resource);
 885                         ns->ns_lvbo->lvbo_update(resource, NULL, 0, 1);
 886                         LDLM_RESOURCE_DELREF(resource);
 887                         ldlm_resource_putref(resource);
 888                 }
 889         }
 890
 891         if (res->dentry != NULL)
 892                 inode = res->dentry->d_inode;
 893
 894         for (i = 0, lnb = res; i < npages; i++, lnb++) {
 895                 if (lnb->page != NULL) {
 896                         page_cache_release(lnb->page);
 897                         lnb->page = NULL;
 898                 }
 899         }
 900
 901         if (inode && (fo->fo_read_cache == 0 ||
 902                         i_size_read(inode) > fo->fo_readcache_max_filesize))
 903                 filter_invalidate_cache(exp->exp_obd, obj, rnb, inode);
 904
 905         if (res->dentry != NULL)
 906                 f_dput(res->dentry);
 907         RETURN(rc);
 908 }
 909
 910 void filter_grant_commit(struct obd_export *exp, int niocount,
 911                          struct niobuf_local *res)
 912 {
 913         struct filter_obd *filter = &exp->exp_obd->u.filter;
 914         struct niobuf_local *lnb = res;
 915         unsigned long pending = 0;
 916         int i;
 917
 918         spin_lock(&exp->exp_obd->obd_osfs_lock);
 919         for (i = 0, lnb = res; i < niocount; i++, lnb++)
 920                 pending += lnb->lnb_grant_used;
 921
 922         LASSERTF(exp->exp_filter_data.fed_pending >= pending,
 923                  "%s: cli %s/%p fed_pending: %lu grant_used: %lu\n",
 924                  exp->exp_obd->obd_name, exp->exp_client_uuid.uuid, exp,
 925                  exp->exp_filter_data.fed_pending, pending);
 926         exp->exp_filter_data.fed_pending -= pending;
 927         LASSERTF(filter->fo_tot_granted >= pending,
 928                  "%s: cli %s/%p tot_granted: "LPU64" grant_used: %lu\n",
 929                  exp->exp_obd->obd_name, exp->exp_client_uuid.uuid, exp,
 930                  exp->exp_obd->u.filter.fo_tot_granted, pending);
 931         filter->fo_tot_granted -= pending;
 932         LASSERTF(filter->fo_tot_pending >= pending,
 933                  "%s: cli %s/%p tot_pending: "LPU64" grant_used: %lu\n",
 934                  exp->exp_obd->obd_name, exp->exp_client_uuid.uuid, exp,
 935                  filter->fo_tot_pending, pending);
 936         filter->fo_tot_pending -= pending;
 937
 938         spin_unlock(&exp->exp_obd->obd_osfs_lock);
 939 }
 940
 941 int filter_commitrw(int cmd, struct obd_export *exp, struct obdo *oa,
 942                     int objcount, struct obd_ioobj *obj,
 943                     struct niobuf_remote *nb, int npages,
 944                     struct niobuf_local *res, struct obd_trans_info *oti,
 945                     int rc)
 946 {
 947         if (cmd == OBD_BRW_WRITE)
 948                 return filter_commitrw_write(exp, oa, objcount, obj,
 949                                              nb, npages, res, oti, rc);
 950         if (cmd == OBD_BRW_READ)
 951                 return filter_commitrw_read(exp, oa, objcount, obj,
 952                                             nb, npages, res, oti, rc);
 953         LBUG();
 954         return -EPROTO;
 955 }
 956
 957 int filter_brw(int cmd, struct obd_export *exp, struct obd_info *oinfo,
 958                obd_count oa_bufs, struct brw_page *pga,
 959                struct obd_trans_info *oti)
 960 {
 961         struct obd_ioobj ioo;
 962         struct niobuf_local *lnb;
 963         struct niobuf_remote *rnb;
 964         obd_count i;
 965         int ret = 0, npages;
 966         ENTRY;
 967
 968         OBD_ALLOC(lnb, oa_bufs * sizeof(struct niobuf_local));
 969         OBD_ALLOC(rnb, oa_bufs * sizeof(struct niobuf_remote));
 970
 971         if (lnb == NULL || rnb == NULL)
 972                 GOTO(out, ret = -ENOMEM);
 973
 974         for (i = 0; i < oa_bufs; i++) {
 975                 lnb[i].page = pga[i].pg;
 976                 rnb[i].offset = pga[i].off;
 977                 rnb[i].len = pga[i].count;
 978         }
 979
 980         obdo_to_ioobj(oinfo->oi_oa, &ioo);
 981         ioo.ioo_bufcnt = oa_bufs;
 982
 983         npages = oa_bufs;
 984         ret = filter_preprw(cmd, exp, oinfo->oi_oa, 1, &ioo,
 985                             rnb, &npages, lnb, oti, oinfo_capa(oinfo));
 986         if (ret != 0)
 987                 GOTO(out, ret);
 988         LASSERTF(oa_bufs == npages, "%u != %u\n", oa_bufs, npages);
 989
 990         ret = filter_commitrw(cmd, exp, oinfo->oi_oa, 1, &ioo, rnb,
 991                               npages, lnb, oti, ret);
 992
 993 out:
 994         if (lnb)
 995                 OBD_FREE(lnb, oa_bufs * sizeof(struct niobuf_local));
 996         if (rnb)
 997                 OBD_FREE(rnb, oa_bufs * sizeof(struct niobuf_remote));
 998         RETURN(ret);
 999 }