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  *  linux/fs/obdfilter/filter_io.c
   5  *
   6  *  Copyright (c) 2001-2003 Cluster File Systems, Inc.
   7  *   Author: Peter Braam <braam@clusterfs.com>
   8  *   Author: Andreas Dilger <adilger@clusterfs.com>
   9  *   Author: Phil Schwan <phil@clusterfs.com>
  10  *
  11  *   This file is part of Lustre, http://www.lustre.org.
  12  *
  13  *   Lustre is free software; you can redistribute it and/or
  14  *   modify it under the terms of version 2 of the GNU General Public
  15  *   License as published by the Free Software Foundation.
  16  *
  17  *   Lustre is distributed in the hope that it will be useful,
  18  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  *   GNU General Public License for more details.
  21  *
  22  *   You should have received a copy of the GNU General Public License
  23  *   along with Lustre; if not, write to the Free Software
  24  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  25  */
  26
  27 #define DEBUG_SUBSYSTEM S_FILTER
  28
  29 #include <linux/config.h>
  30 #include <linux/module.h>
  31 #include <linux/pagemap.h> // XXX kill me soon
  32 #include <linux/version.h>
  33
  34 #include <linux/obd_class.h>
  35 #include <linux/lustre_fsfilt.h>
  36 #include <linux/lustre_smfs.h>
  37 #include <linux/lustre_snap.h>
  38 #include "filter_internal.h"
  39
  40 int *obdfilter_created_scratchpad;
  41
  42 static int filter_alloc_dio_page(struct obd_device *obd, struct inode *inode,
  43                                  struct niobuf_local *lnb)
  44
  45 {
  46         struct page *page;
  47         ENTRY;
  48
  49         page = alloc_pages(GFP_HIGHUSER, 0);
  50         if (page == NULL) {
  51                 CERROR("no memory for a temp page\n");
  52                 lnb->rc = -ENOMEM;
  53                 RETURN(-ENOMEM);
  54         }
  55
  56 #if 0
  57         POISON_PAGE(page, 0xf1);
  58         if (lnb->len != PAGE_SIZE) {
  59                 memset(kmap(page) + lnb->len, 0, PAGE_SIZE - lnb->len);
  60                 kunmap(page);
  61         }
  62 #endif
  63         page->index = lnb->offset >> PAGE_SHIFT;
  64
  65         lnb->page = page;
  66
  67         RETURN(0);
  68 }
  69
  70 void filter_free_dio_pages(int objcount, struct obd_ioobj *obj,
  71                            int niocount, struct niobuf_local *res)
  72 {
  73         int i, j;
  74
  75         for (i = 0; i < objcount; i++, obj++) {
  76                 for (j = 0 ; j < obj->ioo_bufcnt ; j++, res++) {
  77                         if (res->page != NULL) {
  78                                 __free_page(res->page);
  79                                 res->page = NULL;
  80                         }
  81                 }
  82         }
  83 }
  84
  85 /* Grab the dirty and seen grant announcements from the incoming obdo.
  86  * We will later calculate the clients new grant and return it.
  87  * Caller must hold osfs lock */
  88 static void filter_grant_incoming(struct obd_export *exp, struct obdo *oa)
  89 {
  90         struct filter_export_data *fed;
  91         struct obd_device *obd = exp->exp_obd;
  92         static unsigned long last_msg;
  93         static int last_count;
  94         int mask = D_CACHE;
  95         ENTRY;
  96
  97         LASSERT_SPIN_LOCKED(&obd->obd_osfs_lock);
  98
  99         if ((oa->o_valid & (OBD_MD_FLBLOCKS|OBD_MD_FLGRANT)) !=
 100                                         (OBD_MD_FLBLOCKS|OBD_MD_FLGRANT)) {
 101                 oa->o_valid &= ~OBD_MD_FLGRANT;
 102                 EXIT;
 103                 return;
 104         }
 105
 106         fed = &exp->exp_filter_data;
 107
 108         /* Don't print this to the console the first time it happens, since
 109          * it can happen legitimately on occasion, but only rarely. */
 110         if (time_after(jiffies, last_msg + 60 * HZ)) {
 111                 last_count = 0;
 112                 last_msg = jiffies;
 113         }
 114         if ((last_count & (-last_count)) == last_count)
 115                 mask = D_WARNING;
 116         last_count++;
 117
 118         /* Add some margin, since there is a small race if other RPCs arrive
 119          * out-or-order and have already consumed some grant.  We want to
 120          * leave this here in case there is a large error in accounting. */
 121         CDEBUG(oa->o_grant > fed->fed_grant + FILTER_GRANT_CHUNK ? mask:D_CACHE,
 122                "%s: cli %s/%p reports grant: "LPU64" dropped: %u, local: %lu\n",
 123                obd->obd_name, exp->exp_client_uuid.uuid, exp, oa->o_grant,
 124                oa->o_dropped, fed->fed_grant);
 125
 126         /* Update our accounting now so that statfs takes it into account.
 127          * Note that fed_dirty is only approximate and can become incorrect
 128          * if RPCs arrive out-of-order.  No important calculations depend
 129          * on fed_dirty however. */
 130         obd->u.filter.fo_tot_dirty += oa->o_dirty - fed->fed_dirty;
 131         if (fed->fed_grant < oa->o_dropped) {
 132                 CERROR("%s: cli %s/%p reports %u dropped > fed_grant %lu\n",
 133                        obd->obd_name, exp->exp_client_uuid.uuid, exp,
 134                        oa->o_dropped, fed->fed_grant);
 135                 oa->o_dropped = 0;
 136         }
 137         if (obd->u.filter.fo_tot_granted < oa->o_dropped) {
 138                 CERROR("%s: cli %s/%p reports %u dropped > tot_grant "LPU64"\n",
 139                        obd->obd_name, exp->exp_client_uuid.uuid, exp,
 140                        oa->o_dropped, obd->u.filter.fo_tot_granted);
 141                 oa->o_dropped = 0;
 142         }
 143         obd->u.filter.fo_tot_granted -= oa->o_dropped;
 144         fed->fed_grant -= oa->o_dropped;
 145         fed->fed_dirty = oa->o_dirty;
 146         EXIT;
 147 }
 148
 149 #define GRANT_FOR_LLOG(obd) 16
 150
 151 /* Figure out how much space is available between what we've granted
 152  * and what remains in the filesystem.  Compensate for ext3 indirect
 153  * block overhead when computing how much free space is left ungranted.
 154  *
 155  * Caller must hold obd_osfs_lock. */
 156 obd_size filter_grant_space_left(struct obd_export *exp)
 157 {
 158         struct obd_device *obd = exp->exp_obd;
 159         int blockbits = obd->u.filter.fo_sb->s_blocksize_bits;
 160         obd_size tot_granted = obd->u.filter.fo_tot_granted, avail, left = 0;
 161         int rc, statfs_done = 0;
 162
 163         LASSERT_SPIN_LOCKED(&obd->obd_osfs_lock);
 164
 165         if (time_before(obd->obd_osfs_age, jiffies - HZ)) {
 166 restat:
 167                 rc = fsfilt_statfs(obd, obd->u.filter.fo_sb, jiffies + 1);
 168                 if (rc) /* N.B. statfs can't really fail */
 169                         RETURN(0);
 170                 statfs_done = 1;
 171         }
 172
 173         avail = obd->obd_osfs.os_bavail;
 174         left = avail - (avail >> (blockbits - 3)); /* (d)indirect */
 175         if (left > GRANT_FOR_LLOG(obd)) {
 176                 left = (left - GRANT_FOR_LLOG(obd)) << blockbits;
 177         } else {
 178                 left = 0 /* << blockbits */;
 179         }
 180
 181         if (!statfs_done && left < 32 * FILTER_GRANT_CHUNK + tot_granted) {
 182                 CDEBUG(D_CACHE, "fs has no space left and statfs too old\n");
 183                 goto restat;
 184         }
 185
 186         if (left >= tot_granted) {
 187                 left -= tot_granted;
 188         } else {
 189                 static unsigned long next;
 190                 if (left < tot_granted - obd->u.filter.fo_tot_pending &&
 191                     time_after(jiffies, next)) {
 192                         spin_unlock(&obd->obd_osfs_lock);
 193                         CERROR("%s: cli %s/%p grant "LPU64" > available "
 194                                LPU64" and pending "LPU64"\n", obd->obd_name,
 195                                exp->exp_client_uuid.uuid, exp, tot_granted,
 196                                left, obd->u.filter.fo_tot_pending);
 197                         if (next == 0)
 198                                 portals_debug_dumplog();
 199                         next = jiffies + 20 * HZ;
 200                         spin_lock(&obd->obd_osfs_lock);
 201                 }
 202                 left = 0;
 203         }
 204
 205         CDEBUG(D_CACHE, "%s: cli %s/%p free: "LPU64" avail: "LPU64" grant "LPU64
 206                " left: "LPU64" pending: "LPU64"\n", obd->obd_name,
 207                exp->exp_client_uuid.uuid, exp,
 208                obd->obd_osfs.os_bfree << blockbits, avail << blockbits,
 209                tot_granted, left, obd->u.filter.fo_tot_pending);
 210
 211         return left;
 212 }
 213
 214 /* Calculate how much grant space to allocate to this client, based on how
 215  * much space is currently free and how much of that is already granted.
 216  *
 217  * Caller must hold obd_osfs_lock. */
 218 long filter_grant(struct obd_export *exp, obd_size current_grant,
 219                   obd_size want, obd_size fs_space_left)
 220 {
 221         struct obd_device *obd = exp->exp_obd;
 222         struct filter_export_data *fed = &exp->exp_filter_data;
 223         int blockbits = obd->u.filter.fo_sb->s_blocksize_bits;
 224         __u64 grant = 0;
 225
 226         LASSERT_SPIN_LOCKED(&obd->obd_osfs_lock);
 227
 228         /* Grant some fraction of the client's requested grant space so that
 229          * they are not always waiting for write credits (not all of it to
 230          * avoid overgranting in face of multiple RPCs in flight).  This
 231          * essentially will be able to control the OSC_MAX_RIF for a client.
 232          *
 233          * If we do have a large disparity between what the client thinks it
 234          * has and what we think it has, don't grant very much and let the
 235          * client consume its grant first.  Either it just has lots of RPCs
 236          * in flight, or it was evicted and its grants will soon be used up. */
 237         if (current_grant < want &&
 238             current_grant < fed->fed_grant + FILTER_GRANT_CHUNK) {
 239                 grant = min((want >> blockbits) / 2,
 240                             (fs_space_left >> blockbits) / 8);
 241                 grant <<= blockbits;
 242
 243                 if (grant) {
 244                         if (grant > FILTER_GRANT_CHUNK)
 245                                 grant = FILTER_GRANT_CHUNK;
 246
 247                         obd->u.filter.fo_tot_granted += grant;
 248                         fed->fed_grant += grant;
 249                 }
 250         }
 251
 252         CDEBUG(D_CACHE,"%s: cli %s/%p wants: "LPU64" granting: "LPU64"\n",
 253                obd->obd_name, exp->exp_client_uuid.uuid, exp, want, grant);
 254         CDEBUG(D_CACHE,
 255                "%s: cli %s/%p tot cached:"LPU64" granted:"LPU64
 256                " num_exports: %d\n", obd->obd_name, exp->exp_client_uuid.uuid,
 257                exp, obd->u.filter.fo_tot_dirty,
 258                obd->u.filter.fo_tot_granted, obd->obd_num_exports);
 259
 260         return grant;
 261 }
 262
 263 static int filter_preprw_read(int cmd, struct obd_export *exp, struct obdo *oa,
 264                               int objcount, struct obd_ioobj *obj,
 265                               int niocount, struct niobuf_remote *nb,
 266                               struct niobuf_local *res,
 267                               struct obd_trans_info *oti)
 268 {
 269         struct obd_device *obd = exp->exp_obd;
 270         struct lvfs_run_ctxt saved;
 271         struct niobuf_remote *rnb;
 272         struct niobuf_local *lnb;
 273         struct dentry *dentry = NULL;
 274         struct inode *inode;
 275         void *iobuf = NULL;
 276         int rc = 0, i, tot_bytes = 0;
 277         unsigned long now = jiffies;
 278         ENTRY;
 279
 280         /* We are currently not supporting multi-obj BRW_READ RPCS at all.
 281          * When we do this function's dentry cleanup will need to be fixed */
 282         LASSERTF(objcount == 1, "%d\n", objcount);
 283         LASSERTF(obj->ioo_bufcnt > 0, "%d\n", obj->ioo_bufcnt);
 284
 285         if (oa && oa->o_valid & OBD_MD_FLGRANT) {
 286                 spin_lock(&obd->obd_osfs_lock);
 287                 filter_grant_incoming(exp, oa);
 288
 289                 oa->o_grant = 0;
 290                 spin_unlock(&obd->obd_osfs_lock);
 291         }
 292
 293         memset(res, 0, niocount * sizeof(*res));
 294
 295         push_ctxt(&saved, &exp->exp_obd->obd_lvfs_ctxt, NULL);
 296         rc = filter_alloc_iobuf(OBD_BRW_READ, obj->ioo_bufcnt, &iobuf);
 297         if (rc)
 298                 GOTO(cleanup, rc);
 299
 300         dentry = filter_oa2dentry(obd, oa);
 301         if (IS_ERR(dentry))
 302                 GOTO(cleanup, rc = PTR_ERR(dentry));
 303
 304         if (dentry->d_inode == NULL) {
 305                 CERROR("trying to BRW to non-existent file "LPU64"\n",
 306                                obj->ioo_id);
 307                 GOTO(cleanup, rc = -ENOENT);
 308         }
 309
 310         inode = dentry->d_inode;
 311
 312         fsfilt_check_slow(now, obd_timeout, "preprw_read setup");
 313
 314         for (i = 0, lnb = res, rnb = nb; i < obj->ioo_bufcnt;
 315              i++, rnb++, lnb++) {
 316                 lnb->dentry = dentry;
 317                 lnb->offset = rnb->offset;
 318                 lnb->len    = rnb->len;
 319                 lnb->flags  = rnb->flags;
 320
 321                 if (inode->i_size <= rnb->offset)
 322                       /* If there's no more data, abort early.
 323                       * lnb->page == NULL and lnb->rc == 0, so it's
 324                       * easy to detect later. */
 325                         break;
 326                 else
 327                         rc = filter_alloc_dio_page(obd, inode, lnb);
 328                 if (rc) {
 329                         CDEBUG(rc == -ENOSPC ? D_INODE : D_ERROR,
 330                              "page err %u@"LPU64" %u/%u %p: rc %d\n",
 331                               lnb->len, lnb->offset, i, obj->ioo_bufcnt,
 332                               dentry, rc);
 333                         GOTO(cleanup, rc);
 334                 }
 335
 336                 if (inode->i_size < lnb->offset + lnb->len - 1)
 337                         lnb->rc = inode->i_size - lnb->offset;
 338                 else
 339                         lnb->rc = lnb->len;
 340
 341                 tot_bytes += lnb->rc;
 342
 343                 filter_iobuf_add_page(obd, iobuf, inode, lnb->page);
 344         }
 345
 346         fsfilt_check_slow(now, obd_timeout, "start_page_read");
 347
 348         rc = filter_direct_io(OBD_BRW_READ, dentry, iobuf, exp,
 349                               NULL, NULL, NULL);
 350         if (rc)
 351                 GOTO(cleanup, rc);
 352
 353         lprocfs_counter_add(obd->obd_stats, LPROC_FILTER_READ_BYTES, tot_bytes);
 354
 355         filter_tally_read(&exp->exp_obd->u.filter, res, niocount);
 356
 357         EXIT;
 358
 359 cleanup:
 360         if (rc != 0) {
 361                 filter_free_dio_pages(objcount, obj, niocount, res);
 362
 363                 if (dentry != NULL)
 364                         f_dput(dentry);
 365                 else
 366                         CERROR("NULL dentry in cleanup -- tell CFS\n");
 367         }
 368
 369         if (iobuf != NULL)
 370                 filter_free_iobuf(iobuf);
 371
 372         pop_ctxt(&saved, &exp->exp_obd->obd_lvfs_ctxt, NULL);
 373         if (rc)
 374                 CERROR("io error %d\n", rc);
 375         return rc;
 376 }
 377
 378 /* When clients have dirtied as much space as they've been granted they
 379  * fall through to sync writes.  These sync writes haven't been expressed
 380  * in grants and need to error with ENOSPC when there isn't room in the
 381  * filesystem for them after grants are taken into account.  However,
 382  * writeback of the dirty data that was already granted space can write
 383  * right on through.
 384  *
 385  * Caller must hold obd_osfs_lock. */
 386 static int filter_grant_check(struct obd_export *exp, int objcount,
 387                               struct fsfilt_objinfo *fso, int niocount,
 388                               struct niobuf_remote *rnb,
 389                               struct niobuf_local *lnb, obd_size *left,
 390                               struct inode *inode)
 391 {
 392         struct filter_export_data *fed = &exp->exp_filter_data;
 393         int blocksize = exp->exp_obd->u.filter.fo_sb->s_blocksize;
 394         unsigned long used = 0, ungranted = 0, using;
 395         int i, rc = -ENOSPC, obj, n = 0, mask = D_CACHE;
 396
 397         LASSERT_SPIN_LOCKED(&exp->exp_obd->obd_osfs_lock);
 398
 399         for (obj = 0; obj < objcount; obj++) {
 400                 for (i = 0; i < fso[obj].fso_bufcnt; i++, n++) {
 401                         int tmp, bytes;
 402
 403                         /* FIXME: this is calculated with PAGE_SIZE on client */
 404                         bytes = rnb[n].len;
 405                         bytes += rnb[n].offset & (blocksize - 1);
 406                         tmp = (rnb[n].offset + rnb[n].len) & (blocksize - 1);
 407                         if (tmp)
 408                                 bytes += blocksize - tmp;
 409
 410                         if (rnb[n].flags & OBD_BRW_FROM_GRANT) {
 411                                 if (fed->fed_grant < used + bytes) {
 412                                         CDEBUG(D_CACHE,
 413                                                "%s: cli %s/%p claims %ld+%d "
 414                                                "GRANT, real grant %lu idx %d\n",
 415                                                exp->exp_obd->obd_name,
 416                                                exp->exp_client_uuid.uuid, exp,
 417                                                used, bytes, fed->fed_grant, n);
 418                                         mask = D_ERROR;
 419                                 } else {
 420                                         used += bytes;
 421                                         rnb[n].flags |= OBD_BRW_GRANTED;
 422                                         lnb[n].lnb_grant_used = bytes;
 423                                         CDEBUG(0, "idx %d used=%lu\n", n, used);
 424                                         rc = 0;
 425                                         continue;
 426                                 }
 427                         }
 428                         if (*left > ungranted) {
 429                                 /* if enough space, pretend it was granted */
 430                                 ungranted += bytes;
 431                                 rnb[n].flags |= OBD_BRW_GRANTED;
 432                                 CDEBUG(0, "idx %d ungranted=%lu\n",n,ungranted);
 433                                 rc = 0;
 434                                 continue;
 435                         }
 436
 437                         /* We can't check for already-mapped blocks here, as
 438                          * it requires dropping the osfs lock to do the bmap.
 439                          * Instead, we return ENOSPC and in that case we need
 440                          * to go through and verify if all of the blocks not
 441                          * marked BRW_GRANTED are already mapped and we can
 442                          * ignore this error. */
 443                         lnb[n].rc = -ENOSPC;
 444                         rnb[n].flags &= OBD_BRW_GRANTED;
 445                         CDEBUG(D_CACHE,"%s: cli %s/%p idx %d no space for %d\n",
 446                                exp->exp_obd->obd_name,
 447                                exp->exp_client_uuid.uuid, exp, n, bytes);
 448                 }
 449         }
 450
 451         /* Now substract what client have used already.  We don't subtract
 452          * this from the tot_granted yet, so that other client's can't grab
 453          * that space before we have actually allocated our blocks.  That
 454          * happens in filter_grant_commit() after the writes are done. */
 455         *left -= ungranted;
 456         fed->fed_grant -= used;
 457         fed->fed_pending += used;
 458         exp->exp_obd->u.filter.fo_tot_pending += used;
 459
 460         CDEBUG(mask,
 461                "%s: cli %s/%p used: %lu ungranted: %lu grant: %lu dirty: %lu\n",
 462                exp->exp_obd->obd_name, exp->exp_client_uuid.uuid, exp, used,
 463                ungranted, fed->fed_grant, fed->fed_dirty);
 464
 465         /* Rough calc in case we don't refresh cached statfs data */
 466         using = (used + ungranted + 1 ) >>
 467                 exp->exp_obd->u.filter.fo_sb->s_blocksize_bits;
 468         if (exp->exp_obd->obd_osfs.os_bavail > using)
 469                 exp->exp_obd->obd_osfs.os_bavail -= using;
 470         else
 471                 exp->exp_obd->obd_osfs.os_bavail = 0;
 472
 473         if (fed->fed_dirty < used) {
 474                 CERROR("%s: cli %s/%p claims used %lu > fed_dirty %lu\n",
 475                        exp->exp_obd->obd_name, exp->exp_client_uuid.uuid, exp,
 476                        used, fed->fed_dirty);
 477                 used = fed->fed_dirty;
 478         }
 479         exp->exp_obd->u.filter.fo_tot_dirty -= used;
 480         fed->fed_dirty -= used;
 481
 482         return rc;
 483 }
 484
 485 /* If we ever start to support multi-object BRW RPCs, we will need to get locks
 486  * on mulitple inodes.  That isn't all, because there still exists the
 487  * possibility of a truncate starting a new transaction while holding the ext3
 488  * rwsem = write while some writes (which have started their transactions here)
 489  * blocking on the ext3 rwsem = read => lock inversion.
 490  *
 491  * The handling gets very ugly when dealing with locked pages.  It may be easier
 492  * to just get rid of the locked page code (which has problems of its own) and
 493  * either discover we do not need it anymore (i.e. it was a symptom of another
 494  * bug) or ensure we get the page locks in an appropriate order. */
 495 static int filter_preprw_write(int cmd, struct obd_export *exp, struct obdo *oa,
 496                                int objcount, struct obd_ioobj *obj,
 497                                int niocount, struct niobuf_remote *nb,
 498                                struct niobuf_local *res,
 499                                struct obd_trans_info *oti)
 500 {
 501         struct lvfs_run_ctxt saved;
 502         struct niobuf_remote *rnb;
 503         struct niobuf_local *lnb = res;
 504         struct fsfilt_objinfo fso;
 505         struct dentry *dentry = NULL;
 506         void *iobuf;
 507         obd_size left;
 508         unsigned long now = jiffies;
 509         int rc = 0, i, tot_bytes = 0, cleanup_phase = 0;
 510         ENTRY;
 511         LASSERT(objcount == 1);
 512         LASSERT(obj->ioo_bufcnt > 0);
 513
 514         memset(res, 0, niocount * sizeof(*res));
 515
 516         rc = filter_alloc_iobuf(OBD_BRW_READ, obj->ioo_bufcnt, &iobuf);
 517         if (rc)
 518                 GOTO(cleanup, rc);
 519         cleanup_phase = 1;
 520
 521         push_ctxt(&saved, &exp->exp_obd->obd_lvfs_ctxt, NULL);
 522         dentry = filter_id2dentry(exp->exp_obd, NULL, obj->ioo_gr,
 523                                   obj->ioo_id);
 524         if (IS_ERR(dentry))
 525                 GOTO(cleanup, rc = PTR_ERR(dentry));
 526
 527         cleanup_phase = 2;
 528
 529         if (dentry->d_inode == NULL) {
 530                 CERROR("trying to BRW to non-existent file "LPU64"\n",
 531                        obj->ioo_id);
 532                 GOTO(cleanup, rc = -ENOENT);
 533         }
 534
 535         fso.fso_dentry = dentry;
 536         fso.fso_bufcnt = obj->ioo_bufcnt;
 537
 538         fsfilt_check_slow(now, obd_timeout, "preprw_write setup");
 539
 540         spin_lock(&exp->exp_obd->obd_osfs_lock);
 541         if (oa)
 542                 filter_grant_incoming(exp, oa);
 543
 544         cleanup_phase = 3;
 545
 546         left = filter_grant_space_left(exp);
 547
 548         rc = filter_grant_check(exp, objcount, &fso, niocount, nb, res,
 549                                 &left, dentry->d_inode);
 550         if (oa && oa->o_valid & OBD_MD_FLGRANT)
 551                 oa->o_grant = filter_grant(exp,oa->o_grant,oa->o_undirty,left);
 552
 553         /* We're finishing using body->oa as an input variable, so reset
 554          * o_valid here. */
 555         oa->o_valid = 0;
 556
 557         spin_unlock(&exp->exp_obd->obd_osfs_lock);
 558
 559         if (rc)
 560                 GOTO(cleanup, rc);
 561
 562         for (i = 0, rnb = nb, lnb = res; i < obj->ioo_bufcnt;
 563              i++, lnb++, rnb++) {
 564                 /* We still set up for ungranted pages so that granted pages
 565                  * can be written to disk as they were promised, and portals
 566                  * needs to keep the pages all aligned properly. */
 567                 lnb->dentry = dentry;
 568                 lnb->offset = rnb->offset;
 569                 lnb->len    = rnb->len;
 570                 lnb->flags  = rnb->flags;
 571
 572                 rc = filter_alloc_dio_page(exp->exp_obd, dentry->d_inode,lnb);
 573                 if (rc) {
 574                         CERROR("page err %u@"LPU64" %u/%u %p: rc %d\n",
 575                                lnb->len, lnb->offset,
 576                                i, obj->ioo_bufcnt, dentry, rc);
 577                         GOTO(cleanup, rc);
 578                 }
 579                 cleanup_phase = 4;
 580
 581                 /* If the filter writes a partial page, then has the file
 582                  * extended, the client will read in the whole page.  the
 583                  * filter has to be careful to zero the rest of the partial
 584                  * page on disk.  we do it by hand for partial extending
 585                  * writes, send_bio() is responsible for zeroing pages when
 586                  * asked to read unmapped blocks -- brw_kiovec() does this. */
 587                 if (lnb->len != PAGE_SIZE) {
 588                         if (lnb->offset + lnb->len < dentry->d_inode->i_size) {
 589                                 filter_iobuf_add_page(exp->exp_obd, iobuf,
 590                                                       dentry->d_inode,
 591                                                       lnb->page);
 592                         } else {
 593                                 memset(kmap(lnb->page) + lnb->len, 0,
 594                                        PAGE_SIZE - lnb->len);
 595                                 kunmap(lnb->page);
 596                         }
 597                 }
 598                 if (lnb->rc == 0)
 599                         tot_bytes += lnb->len;
 600         }
 601
 602         rc = filter_direct_io(OBD_BRW_READ, dentry, iobuf, exp,
 603                               NULL, NULL, NULL);
 604
 605         fsfilt_check_slow(now, obd_timeout, "start_page_write");
 606
 607         lprocfs_counter_add(exp->exp_obd->obd_stats, LPROC_FILTER_WRITE_BYTES,
 608                             tot_bytes);
 609         EXIT;
 610 cleanup:
 611         switch(cleanup_phase) {
 612         case 4:
 613                 if (rc)
 614                         filter_free_dio_pages(objcount, obj, niocount, res);
 615         case 3:
 616                 pop_ctxt(&saved, &exp->exp_obd->obd_lvfs_ctxt, NULL);
 617                 filter_free_iobuf(iobuf);
 618         case 2:
 619                 if (rc)
 620                         f_dput(dentry);
 621                 break;
 622         case 1:
 623                 spin_lock(&exp->exp_obd->obd_osfs_lock);
 624                 if (oa)
 625                         filter_grant_incoming(exp, oa);
 626                 spin_unlock(&exp->exp_obd->obd_osfs_lock);
 627                 pop_ctxt(&saved, &exp->exp_obd->obd_lvfs_ctxt, NULL);
 628                 filter_free_iobuf(iobuf);
 629                 break;
 630         default:;
 631
 632         }
 633         RETURN(rc);
 634 }
 635
 636 int filter_preprw(int cmd, struct obd_export *exp, struct obdo *oa,
 637                   int objcount, struct obd_ioobj *obj, int niocount,
 638                   struct niobuf_remote *nb, struct niobuf_local *res,
 639                   struct obd_trans_info *oti)
 640 {
 641         if (cmd == OBD_BRW_WRITE)
 642                 return filter_preprw_write(cmd, exp, oa, objcount, obj,
 643                                            niocount, nb, res, oti);
 644
 645         if (cmd == OBD_BRW_READ)
 646                 return filter_preprw_read(cmd, exp, oa, objcount, obj,
 647                                           niocount, nb, res, oti);
 648
 649         LBUG();
 650         return -EPROTO;
 651 }
 652
 653 void filter_release_read_page(struct filter_obd *filter, struct inode *inode,
 654                               struct page *page)
 655 {
 656         int drop = 0;
 657
 658         if (inode != NULL &&
 659             (inode->i_size > filter->fo_readcache_max_filesize))
 660                 drop = 1;
 661
 662         /* drop from cache like truncate_list_pages() */
 663         if (drop && !TryLockPage(page)) {
 664                 if (page->mapping)
 665                         ll_truncate_complete_page(page);
 666                 unlock_page(page);
 667         }
 668         page_cache_release(page);
 669 }
 670
 671 static int filter_commitrw_read(struct obd_export *exp, struct obdo *oa,
 672                                 int objcount, struct obd_ioobj *obj,
 673                                 int niocount, struct niobuf_local *res,
 674                                 struct obd_trans_info *oti, int rc)
 675 {
 676         struct inode *inode = NULL;
 677         ENTRY;
 678
 679         if (res->dentry != NULL)
 680                 inode = res->dentry->d_inode;
 681
 682         filter_free_dio_pages(objcount, obj, niocount, res);
 683
 684         if (res->dentry != NULL)
 685                 f_dput(res->dentry);
 686         RETURN(rc);
 687 }
 688
 689 void flip_into_page_cache(struct inode *inode, struct page *new_page)
 690 {
 691         struct page *old_page;
 692         int rc;
 693
 694         do {
 695                 /* the dlm is protecting us from read/write concurrency, so we
 696                  * expect this find_lock_page to return quickly.  even if we
 697                  * race with another writer it won't be doing much work with
 698                  * the page locked.  we do this 'cause t_c_p expects a
 699                  * locked page, and it wants to grab the pagecache lock
 700                  * as well. */
 701                 old_page = find_lock_page(inode->i_mapping, new_page->index);
 702                 if (old_page) {
 703                         ll_truncate_complete_page(old_page);
 704                         unlock_page(old_page);
 705                         page_cache_release(old_page);
 706                 }
 707
 708 #if 0 /* this should be a /proc tunable someday */
 709                 /* racing o_directs (no locking ioctl) could race adding
 710                  * their pages, so we repeat the page invalidation unless
 711                  * we successfully added our new page */
 712                 rc = add_to_page_cache_unique(new_page, inode->i_mapping,
 713                                               new_page->index,
 714                                               page_hash(inode->i_mapping,
 715                                                         new_page->index));
 716                 if (rc == 0) {
 717                         /* add_to_page_cache clears uptodate|dirty and locks
 718                          * the page */
 719                         SetPageUptodate(new_page);
 720                         unlock_page(new_page);
 721                 }
 722 #else
 723                 rc = 0;
 724 #endif
 725         } while (rc != 0);
 726 }
 727
 728 void filter_grant_commit(struct obd_export *exp, int niocount,
 729                          struct niobuf_local *res)
 730 {
 731         struct filter_obd *filter = &exp->exp_obd->u.filter;
 732         struct niobuf_local *lnb = res;
 733         unsigned long pending = 0;
 734         int i;
 735
 736         spin_lock(&exp->exp_obd->obd_osfs_lock);
 737         for (i = 0, lnb = res; i < niocount; i++, lnb++)
 738                 pending += lnb->lnb_grant_used;
 739
 740         LASSERTF(exp->exp_filter_data.fed_pending >= pending,
 741                  "%s: cli %s/%p fed_pending: %lu grant_used: %lu\n",
 742                  exp->exp_obd->obd_name, exp->exp_client_uuid.uuid, exp,
 743                  exp->exp_filter_data.fed_pending, pending);
 744         exp->exp_filter_data.fed_pending -= pending;
 745         LASSERTF(filter->fo_tot_granted >= pending,
 746                  "%s: cli %s/%p tot_granted: "LPU64" grant_used: %lu\n",
 747                  exp->exp_obd->obd_name, exp->exp_client_uuid.uuid, exp,
 748                  exp->exp_obd->u.filter.fo_tot_granted, pending);
 749         filter->fo_tot_granted -= pending;
 750         LASSERTF(filter->fo_tot_pending >= pending,
 751                  "%s: cli %s/%p tot_pending: "LPU64" grant_used: %lu\n",
 752                  exp->exp_obd->obd_name, exp->exp_client_uuid.uuid, exp,
 753                  filter->fo_tot_pending, pending);
 754         filter->fo_tot_pending -= pending;
 755
 756         spin_unlock(&exp->exp_obd->obd_osfs_lock);
 757 }
 758 int filter_do_cow(struct obd_export *exp, struct obd_ioobj *obj,
 759                   int nioo, struct niobuf_remote *rnb)
 760 {
 761         struct dentry *dentry;
 762         struct lvfs_run_ctxt saved;
 763         struct write_extents *extents = NULL;
 764         int j, rc = 0, numexts = 0, flags = 0;
 765
 766         ENTRY;
 767
 768         LASSERT(nioo == 1);
 769
 770         push_ctxt(&saved, &exp->exp_obd->obd_lvfs_ctxt, NULL);
 771
 772         dentry = filter_id2dentry(exp->exp_obd, NULL, obj->ioo_gr,
 773                                   obj->ioo_id);
 774         if (IS_ERR(dentry)) {
 775                 pop_ctxt(&saved, &exp->exp_obd->obd_lvfs_ctxt, NULL);
 776                 RETURN (PTR_ERR(dentry));
 777         }
 778
 779         if (dentry->d_inode == NULL) {
 780                 CERROR("trying to write extents to non-existent file "LPU64"\n",
 781                        obj->ioo_id);
 782                 GOTO(cleanup, rc = -ENOENT);
 783         }
 784
 785         flags = fsfilt_get_fs_flags(exp->exp_obd, dentry);
 786         if (!(flags & SM_DO_COW)) {
 787                 GOTO(cleanup, rc);
 788         }
 789         OBD_ALLOC(extents, obj->ioo_bufcnt * sizeof(struct write_extents));
 790         if (!extents) {
 791                 CERROR("No Memory\n");
 792                 GOTO(cleanup, rc = -ENOMEM);
 793         }
 794         for (j = 0; j < obj->ioo_bufcnt; j++) {
 795                 if (rnb[j].len != 0) {
 796                         extents[numexts].w_count = rnb[j].len;
 797                         extents[numexts].w_pos = rnb[j].offset;
 798                         numexts++;
 799                 }
 800         }
 801         rc = fsfilt_do_write_cow(exp->exp_obd, dentry, extents, numexts);
 802         if (rc) {
 803                 CERROR("Do cow error id "LPU64" rc:%d \n",
 804                         obj->ioo_id, rc);
 805                 GOTO(cleanup, rc);
 806         }
 807
 808 cleanup:
 809         if (extents) {
 810                 OBD_FREE(extents, obj->ioo_bufcnt * sizeof(struct write_extents));
 811         }
 812         f_dput(dentry);
 813         pop_ctxt(&saved, &exp->exp_obd->obd_lvfs_ctxt, NULL);
 814         RETURN(rc);
 815
 816 }
 817 int filter_write_extents(struct obd_export *exp, struct obd_ioobj *obj, int nobj,
 818                          int niocount, struct niobuf_local *local, int rc)
 819 {
 820         struct lvfs_run_ctxt saved;
 821         struct dentry *dentry;
 822         struct niobuf_local *lnb;
 823         __u64  offset = 0;
 824         __u32  len = 0;
 825         int    i, flags;
 826
 827         ENTRY;
 828
 829         LASSERT(nobj == 1);
 830
 831         push_ctxt(&saved, &exp->exp_obd->obd_lvfs_ctxt, NULL);
 832         dentry = filter_id2dentry(exp->exp_obd, NULL, obj->ioo_gr,
 833                                   obj->ioo_id);
 834         if (IS_ERR(dentry)) {
 835                 pop_ctxt(&saved, &exp->exp_obd->obd_lvfs_ctxt, NULL);
 836                 RETURN (PTR_ERR(dentry));
 837         }
 838
 839         if (dentry->d_inode == NULL) {
 840                 CERROR("trying to write extents to non-existent file "LPU64"\n",
 841                        obj->ioo_id);
 842                 GOTO(cleanup, rc = -ENOENT);
 843         }
 844
 845         flags = fsfilt_get_fs_flags(exp->exp_obd, dentry);
 846         if (!(flags & SM_DO_REC)) {
 847                 GOTO(cleanup, rc);
 848         }
 849
 850         for (i = 0, lnb = local; i < obj->ioo_bufcnt; i++, lnb++) {
 851                 if (len == 0) {
 852                         offset = lnb->offset;
 853                         len = lnb->len;
 854                 } else if (lnb->offset == (offset + len)) {
 855                         len += lnb->len;
 856                 } else {
 857                         rc = fsfilt_write_extents(exp->exp_obd, dentry,
 858                                                   offset, len);
 859                         if (rc) {
 860                                 CERROR("write exts off "LPU64" num %u rc:%d\n",
 861                                         offset, len, rc);
 862                                 GOTO(cleanup, rc);
 863                         }
 864                         offset = lnb->offset;
 865                         len = lnb->len;
 866                 }
 867         }
 868         if (len > 0) {
 869                 rc = fsfilt_write_extents(exp->exp_obd, dentry,
 870                                           offset, len);
 871                 if (rc) {
 872                         CERROR("write exts off "LPU64" num %u rc:%d\n",
 873                                 offset, len, rc);
 874                         GOTO(cleanup, rc);
 875                 }
 876         }
 877 cleanup:
 878         f_dput(dentry);
 879         pop_ctxt(&saved, &exp->exp_obd->obd_lvfs_ctxt, NULL);
 880         RETURN(rc);
 881 }
 882
 883 int filter_commitrw(int cmd, struct obd_export *exp, struct obdo *oa,
 884                     int objcount, struct obd_ioobj *obj, int niocount,
 885                     struct niobuf_local *res, struct obd_trans_info *oti,int rc)
 886 {
 887         if (cmd == OBD_BRW_WRITE)
 888                 return filter_commitrw_write(exp, oa, objcount, obj, niocount,
 889                                              res, oti, rc);
 890         if (cmd == OBD_BRW_READ)
 891                 return filter_commitrw_read(exp, oa, objcount, obj, niocount,
 892                                             res, oti, rc);
 893         LBUG();
 894         return -EPROTO;
 895 }
 896
 897 int filter_brw(int cmd, struct obd_export *exp, struct obdo *oa,
 898                struct lov_stripe_md *lsm, obd_count oa_bufs,
 899                struct brw_page *pga, struct obd_trans_info *oti)
 900 {
 901         struct obd_ioobj ioo;
 902         struct niobuf_local *lnb;
 903         struct niobuf_remote *rnb;
 904         obd_count i;
 905         int ret = 0;
 906         ENTRY;
 907
 908         OBD_ALLOC(lnb, oa_bufs * sizeof(struct niobuf_local));
 909         OBD_ALLOC(rnb, oa_bufs * sizeof(struct niobuf_remote));
 910
 911         if (lnb == NULL || rnb == NULL)
 912                 GOTO(out, ret = -ENOMEM);
 913
 914         for (i = 0; i < oa_bufs; i++) {
 915                 rnb[i].offset = pga[i].disk_offset;
 916                 rnb[i].len = pga[i].count;
 917         }
 918
 919         obdo_to_ioobj(oa, &ioo);
 920         ioo.ioo_bufcnt = oa_bufs;
 921
 922         ret = filter_preprw(cmd, exp, oa, 1, &ioo, oa_bufs, rnb, lnb, oti);
 923         if (ret != 0)
 924                 GOTO(out, ret);
 925
 926         for (i = 0; i < oa_bufs; i++) {
 927                 void *virt;
 928                 obd_off off;
 929                 void *addr;
 930
 931                 if (lnb[i].page == NULL)
 932                         break;
 933
 934                 off = pga[i].disk_offset & ~PAGE_MASK;
 935                 virt = kmap(pga[i].pg);
 936                 addr = kmap(lnb[i].page);
 937
 938                 /* 2 kmaps == vanishingly small deadlock opportunity */
 939
 940                 if (cmd & OBD_BRW_WRITE)
 941                         memcpy(addr + off, virt + off, pga[i].count);
 942                 else
 943                         memcpy(virt + off, addr + off, pga[i].count);
 944
 945                 kunmap(lnb[i].page);
 946                 kunmap(pga[i].pg);
 947         }
 948
 949         ret = filter_commitrw(cmd, exp, oa, 1, &ioo, oa_bufs, lnb, oti, ret);
 950
 951 out:
 952         if (lnb)
 953                 OBD_FREE(lnb, oa_bufs * sizeof(struct niobuf_local));
 954         if (rnb)
 955                 OBD_FREE(rnb, oa_bufs * sizeof(struct niobuf_remote));
 956         RETURN(ret);
 957 }