fs/nfs/nfs4filelayout.c

   1 /*
   2  *  Module for the pnfs nfs4 file layout driver.
   3  *  Defines all I/O and Policy interface operations, plus code
   4  *  to register itself with the pNFS client.
   5  *
   6  *  Copyright (c) 2002
   7  *  The Regents of the University of Michigan
   8  *  All Rights Reserved
   9  *
  10  *  Dean Hildebrand <dhildebz@umich.edu>
  11  *
  12  *  Permission is granted to use, copy, create derivative works, and
  13  *  redistribute this software and such derivative works for any purpose,
  14  *  so long as the name of the University of Michigan is not used in
  15  *  any advertising or publicity pertaining to the use or distribution
  16  *  of this software without specific, written prior authorization. If
  17  *  the above copyright notice or any other identification of the
  18  *  University of Michigan is included in any copy of any portion of
  19  *  this software, then the disclaimer below must also be included.
  20  *
  21  *  This software is provided as is, without representation or warranty
  22  *  of any kind either express or implied, including without limitation
  23  *  the implied warranties of merchantability, fitness for a particular
  24  *  purpose, or noninfringement.  The Regents of the University of
  25  *  Michigan shall not be liable for any damages, including special,
  26  *  indirect, incidental, or consequential damages, with respect to any
  27  *  claim arising out of or in connection with the use of the software,
  28  *  even if it has been or is hereafter advised of the possibility of
  29  *  such damages.
  30  */
  31
  32 #include <linux/nfs_fs.h>
  33 #include <linux/nfs_page.h>
  34 #include <linux/module.h>
  35
  36 #include <linux/sunrpc/metrics.h>
  37
  38 #include "internal.h"
  39 #include "delegation.h"
  40 #include "nfs4filelayout.h"
  41
  42 #define NFSDBG_FACILITY         NFSDBG_PNFS_LD
  43
  44 MODULE_LICENSE("GPL");
  45 MODULE_AUTHOR("Dean Hildebrand <dhildebz@umich.edu>");
  46 MODULE_DESCRIPTION("The NFSv4 file layout driver");
  47
  48 #define FILELAYOUT_POLL_RETRY_MAX     (15*HZ)
  49
  50 static loff_t
  51 filelayout_get_dense_offset(struct nfs4_filelayout_segment *flseg,
  52                             loff_t offset)
  53 {
  54         u32 stripe_width = flseg->stripe_unit * flseg->dsaddr->stripe_count;
  55         u64 stripe_no;
  56         u32 rem;
  57
  58         offset -= flseg->pattern_offset;
  59         stripe_no = div_u64(offset, stripe_width);
  60         div_u64_rem(offset, flseg->stripe_unit, &rem);
  61
  62         return stripe_no * flseg->stripe_unit + rem;
  63 }
  64
  65 /* This function is used by the layout driver to calculate the
  66  * offset of the file on the dserver based on whether the
  67  * layout type is STRIPE_DENSE or STRIPE_SPARSE
  68  */
  69 static loff_t
  70 filelayout_get_dserver_offset(struct pnfs_layout_segment *lseg, loff_t offset)
  71 {
  72         struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
  73
  74         switch (flseg->stripe_type) {
  75         case STRIPE_SPARSE:
  76                 return offset;
  77
  78         case STRIPE_DENSE:
  79                 return filelayout_get_dense_offset(flseg, offset);
  80         }
  81
  82         BUG();
  83 }
  84
  85 static int filelayout_async_handle_error(struct rpc_task *task,
  86                                          struct nfs4_state *state,
  87                                          struct nfs_client *clp,
  88                                          int *reset)
  89 {
  90         struct nfs_server *mds_server = NFS_SERVER(state->inode);
  91         struct nfs_client *mds_client = mds_server->nfs_client;
  92
  93         if (task->tk_status >= 0)
  94                 return 0;
  95         *reset = 0;
  96
  97         switch (task->tk_status) {
  98         /* MDS state errors */
  99         case -NFS4ERR_DELEG_REVOKED:
 100         case -NFS4ERR_ADMIN_REVOKED:
 101         case -NFS4ERR_BAD_STATEID:
 102                 nfs_remove_bad_delegation(state->inode);
 103         case -NFS4ERR_OPENMODE:
 104                 nfs4_schedule_stateid_recovery(mds_server, state);
 105                 goto wait_on_recovery;
 106         case -NFS4ERR_EXPIRED:
 107                 nfs4_schedule_stateid_recovery(mds_server, state);
 108                 nfs4_schedule_lease_recovery(mds_client);
 109                 goto wait_on_recovery;
 110         /* DS session errors */
 111         case -NFS4ERR_BADSESSION:
 112         case -NFS4ERR_BADSLOT:
 113         case -NFS4ERR_BAD_HIGH_SLOT:
 114         case -NFS4ERR_DEADSESSION:
 115         case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
 116         case -NFS4ERR_SEQ_FALSE_RETRY:
 117         case -NFS4ERR_SEQ_MISORDERED:
 118                 dprintk("%s ERROR %d, Reset session. Exchangeid "
 119                         "flags 0x%x\n", __func__, task->tk_status,
 120                         clp->cl_exchange_flags);
 121                 nfs4_schedule_session_recovery(clp->cl_session);
 122                 break;
 123         case -NFS4ERR_DELAY:
 124         case -NFS4ERR_GRACE:
 125         case -EKEYEXPIRED:
 126                 rpc_delay(task, FILELAYOUT_POLL_RETRY_MAX);
 127                 break;
 128         case -NFS4ERR_RETRY_UNCACHED_REP:
 129                 break;
 130         default:
 131                 dprintk("%s DS error. Retry through MDS %d\n", __func__,
 132                         task->tk_status);
 133                 *reset = 1;
 134                 break;
 135         }
 136 out:
 137         task->tk_status = 0;
 138         return -EAGAIN;
 139 wait_on_recovery:
 140         rpc_sleep_on(&mds_client->cl_rpcwaitq, task, NULL);
 141         if (test_bit(NFS4CLNT_MANAGER_RUNNING, &mds_client->cl_state) == 0)
 142                 rpc_wake_up_queued_task(&mds_client->cl_rpcwaitq, task);
 143         goto out;
 144 }
 145
 146 /* NFS_PROTO call done callback routines */
 147
 148 static int filelayout_read_done_cb(struct rpc_task *task,
 149                                 struct nfs_read_data *data)
 150 {
 151         struct nfs_pgio_header *hdr = data->header;
 152         int reset = 0;
 153
 154         dprintk("%s DS read\n", __func__);
 155
 156         if (filelayout_async_handle_error(task, data->args.context->state,
 157                                           data->ds_clp, &reset) == -EAGAIN) {
 158                 dprintk("%s calling restart ds_clp %p ds_clp->cl_session %p\n",
 159                         __func__, data->ds_clp, data->ds_clp->cl_session);
 160                 if (reset) {
 161                         pnfs_set_lo_fail(hdr->lseg);
 162                         nfs4_reset_read(task, data);
 163                 }
 164                 rpc_restart_call_prepare(task);
 165                 return -EAGAIN;
 166         }
 167
 168         return 0;
 169 }
 170
 171 /*
 172  * We reference the rpc_cred of the first WRITE that triggers the need for
 173  * a LAYOUTCOMMIT, and use it to send the layoutcommit compound.
 174  * rfc5661 is not clear about which credential should be used.
 175  */
 176 static void
 177 filelayout_set_layoutcommit(struct nfs_write_data *wdata)
 178 {
 179         struct nfs_pgio_header *hdr = wdata->header;
 180
 181         if (FILELAYOUT_LSEG(hdr->lseg)->commit_through_mds ||
 182             wdata->res.verf->committed == NFS_FILE_SYNC)
 183                 return;
 184
 185         pnfs_set_layoutcommit(wdata);
 186         dprintk("%s ionde %lu pls_end_pos %lu\n", __func__, hdr->inode->i_ino,
 187                 (unsigned long) NFS_I(hdr->inode)->layout->plh_lwb);
 188 }
 189
 190 /*
 191  * Call ops for the async read/write cases
 192  * In the case of dense layouts, the offset needs to be reset to its
 193  * original value.
 194  */
 195 static void filelayout_read_prepare(struct rpc_task *task, void *data)
 196 {
 197         struct nfs_read_data *rdata = data;
 198
 199         rdata->read_done_cb = filelayout_read_done_cb;
 200
 201         if (nfs41_setup_sequence(rdata->ds_clp->cl_session,
 202                                 &rdata->args.seq_args, &rdata->res.seq_res,
 203                                 task))
 204                 return;
 205
 206         rpc_call_start(task);
 207 }
 208
 209 static void filelayout_read_call_done(struct rpc_task *task, void *data)
 210 {
 211         struct nfs_read_data *rdata = data;
 212
 213         dprintk("--> %s task->tk_status %d\n", __func__, task->tk_status);
 214
 215         /* Note this may cause RPC to be resent */
 216         rdata->header->mds_ops->rpc_call_done(task, data);
 217 }
 218
 219 static void filelayout_read_count_stats(struct rpc_task *task, void *data)
 220 {
 221         struct nfs_read_data *rdata = data;
 222
 223         rpc_count_iostats(task, NFS_SERVER(rdata->header->inode)->client->cl_metrics);
 224 }
 225
 226 static void filelayout_read_release(void *data)
 227 {
 228         struct nfs_read_data *rdata = data;
 229
 230         rdata->header->mds_ops->rpc_release(data);
 231 }
 232
 233 static int filelayout_write_done_cb(struct rpc_task *task,
 234                                 struct nfs_write_data *data)
 235 {
 236         struct nfs_pgio_header *hdr = data->header;
 237         int reset = 0;
 238
 239         if (filelayout_async_handle_error(task, data->args.context->state,
 240                                           data->ds_clp, &reset) == -EAGAIN) {
 241                 dprintk("%s calling restart ds_clp %p ds_clp->cl_session %p\n",
 242                         __func__, data->ds_clp, data->ds_clp->cl_session);
 243                 if (reset) {
 244                         pnfs_set_lo_fail(hdr->lseg);
 245                         nfs4_reset_write(task, data);
 246                 }
 247                 rpc_restart_call_prepare(task);
 248                 return -EAGAIN;
 249         }
 250
 251         filelayout_set_layoutcommit(data);
 252         return 0;
 253 }
 254
 255 /* Fake up some data that will cause nfs_commit_release to retry the writes. */
 256 static void prepare_to_resend_writes(struct nfs_commit_data *data)
 257 {
 258         struct nfs_page *first = nfs_list_entry(data->pages.next);
 259
 260         data->task.tk_status = 0;
 261         memcpy(data->verf.verifier, first->wb_verf.verifier,
 262                sizeof(first->wb_verf.verifier));
 263         data->verf.verifier[0]++; /* ensure verifier mismatch */
 264 }
 265
 266 static int filelayout_commit_done_cb(struct rpc_task *task,
 267                                      struct nfs_commit_data *data)
 268 {
 269         int reset = 0;
 270
 271         if (filelayout_async_handle_error(task, data->context->state,
 272                                           data->ds_clp, &reset) == -EAGAIN) {
 273                 dprintk("%s calling restart ds_clp %p ds_clp->cl_session %p\n",
 274                         __func__, data->ds_clp, data->ds_clp->cl_session);
 275                 if (reset) {
 276                         prepare_to_resend_writes(data);
 277                         pnfs_set_lo_fail(data->lseg);
 278                 } else
 279                         rpc_restart_call_prepare(task);
 280                 return -EAGAIN;
 281         }
 282
 283         return 0;
 284 }
 285
 286 static void filelayout_write_prepare(struct rpc_task *task, void *data)
 287 {
 288         struct nfs_write_data *wdata = data;
 289
 290         if (nfs41_setup_sequence(wdata->ds_clp->cl_session,
 291                                 &wdata->args.seq_args, &wdata->res.seq_res,
 292                                 task))
 293                 return;
 294
 295         rpc_call_start(task);
 296 }
 297
 298 static void filelayout_write_call_done(struct rpc_task *task, void *data)
 299 {
 300         struct nfs_write_data *wdata = data;
 301
 302         /* Note this may cause RPC to be resent */
 303         wdata->header->mds_ops->rpc_call_done(task, data);
 304 }
 305
 306 static void filelayout_write_count_stats(struct rpc_task *task, void *data)
 307 {
 308         struct nfs_write_data *wdata = data;
 309
 310         rpc_count_iostats(task, NFS_SERVER(wdata->header->inode)->client->cl_metrics);
 311 }
 312
 313 static void filelayout_write_release(void *data)
 314 {
 315         struct nfs_write_data *wdata = data;
 316
 317         wdata->header->mds_ops->rpc_release(data);
 318 }
 319
 320 static void filelayout_commit_prepare(struct rpc_task *task, void *data)
 321 {
 322         struct nfs_commit_data *wdata = data;
 323
 324         if (nfs41_setup_sequence(wdata->ds_clp->cl_session,
 325                                 &wdata->args.seq_args, &wdata->res.seq_res,
 326                                 task))
 327                 return;
 328
 329         rpc_call_start(task);
 330 }
 331
 332 static void filelayout_write_commit_done(struct rpc_task *task, void *data)
 333 {
 334         struct nfs_commit_data *wdata = data;
 335
 336         /* Note this may cause RPC to be resent */
 337         wdata->mds_ops->rpc_call_done(task, data);
 338 }
 339
 340 static void filelayout_commit_count_stats(struct rpc_task *task, void *data)
 341 {
 342         struct nfs_commit_data *cdata = data;
 343
 344         rpc_count_iostats(task, NFS_SERVER(cdata->inode)->client->cl_metrics);
 345 }
 346
 347 static void filelayout_commit_release(void *calldata)
 348 {
 349         struct nfs_commit_data *data = calldata;
 350
 351         data->completion_ops->completion(data);
 352         put_lseg(data->lseg);
 353         nfs_commitdata_release(data);
 354 }
 355
 356 static const struct rpc_call_ops filelayout_read_call_ops = {
 357         .rpc_call_prepare = filelayout_read_prepare,
 358         .rpc_call_done = filelayout_read_call_done,
 359         .rpc_count_stats = filelayout_read_count_stats,
 360         .rpc_release = filelayout_read_release,
 361 };
 362
 363 static const struct rpc_call_ops filelayout_write_call_ops = {
 364         .rpc_call_prepare = filelayout_write_prepare,
 365         .rpc_call_done = filelayout_write_call_done,
 366         .rpc_count_stats = filelayout_write_count_stats,
 367         .rpc_release = filelayout_write_release,
 368 };
 369
 370 static const struct rpc_call_ops filelayout_commit_call_ops = {
 371         .rpc_call_prepare = filelayout_commit_prepare,
 372         .rpc_call_done = filelayout_write_commit_done,
 373         .rpc_count_stats = filelayout_commit_count_stats,
 374         .rpc_release = filelayout_commit_release,
 375 };
 376
 377 static enum pnfs_try_status
 378 filelayout_read_pagelist(struct nfs_read_data *data)
 379 {
 380         struct nfs_pgio_header *hdr = data->header;
 381         struct pnfs_layout_segment *lseg = hdr->lseg;
 382         struct nfs4_pnfs_ds *ds;
 383         loff_t offset = data->args.offset;
 384         u32 j, idx;
 385         struct nfs_fh *fh;
 386         int status;
 387
 388         dprintk("--> %s ino %lu pgbase %u req %Zu@%llu\n",
 389                 __func__, hdr->inode->i_ino,
 390                 data->args.pgbase, (size_t)data->args.count, offset);
 391
 392         /* Retrieve the correct rpc_client for the byte range */
 393         j = nfs4_fl_calc_j_index(lseg, offset);
 394         idx = nfs4_fl_calc_ds_index(lseg, j);
 395         ds = nfs4_fl_prepare_ds(lseg, idx);
 396         if (!ds) {
 397                 /* Either layout fh index faulty, or ds connect failed */
 398                 set_bit(lo_fail_bit(IOMODE_RW), &lseg->pls_layout->plh_flags);
 399                 set_bit(lo_fail_bit(IOMODE_READ), &lseg->pls_layout->plh_flags);
 400                 return PNFS_NOT_ATTEMPTED;
 401         }
 402         dprintk("%s USE DS: %s\n", __func__, ds->ds_remotestr);
 403
 404         /* No multipath support. Use first DS */
 405         data->ds_clp = ds->ds_clp;
 406         fh = nfs4_fl_select_ds_fh(lseg, j);
 407         if (fh)
 408                 data->args.fh = fh;
 409
 410         data->args.offset = filelayout_get_dserver_offset(lseg, offset);
 411         data->mds_offset = offset;
 412
 413         /* Perform an asynchronous read to ds */
 414         status = nfs_initiate_read(ds->ds_clp->cl_rpcclient, data,
 415                                    &filelayout_read_call_ops);
 416         BUG_ON(status != 0);
 417         return PNFS_ATTEMPTED;
 418 }
 419
 420 /* Perform async writes. */
 421 static enum pnfs_try_status
 422 filelayout_write_pagelist(struct nfs_write_data *data, int sync)
 423 {
 424         struct nfs_pgio_header *hdr = data->header;
 425         struct pnfs_layout_segment *lseg = hdr->lseg;
 426         struct nfs4_pnfs_ds *ds;
 427         loff_t offset = data->args.offset;
 428         u32 j, idx;
 429         struct nfs_fh *fh;
 430         int status;
 431
 432         /* Retrieve the correct rpc_client for the byte range */
 433         j = nfs4_fl_calc_j_index(lseg, offset);
 434         idx = nfs4_fl_calc_ds_index(lseg, j);
 435         ds = nfs4_fl_prepare_ds(lseg, idx);
 436         if (!ds) {
 437                 set_bit(lo_fail_bit(IOMODE_RW), &lseg->pls_layout->plh_flags);
 438                 set_bit(lo_fail_bit(IOMODE_READ), &lseg->pls_layout->plh_flags);
 439                 return PNFS_NOT_ATTEMPTED;
 440         }
 441         dprintk("%s ino %lu sync %d req %Zu@%llu DS: %s\n", __func__,
 442                 hdr->inode->i_ino, sync, (size_t) data->args.count, offset,
 443                 ds->ds_remotestr);
 444
 445         data->write_done_cb = filelayout_write_done_cb;
 446         data->ds_clp = ds->ds_clp;
 447         fh = nfs4_fl_select_ds_fh(lseg, j);
 448         if (fh)
 449                 data->args.fh = fh;
 450         /*
 451          * Get the file offset on the dserver. Set the write offset to
 452          * this offset and save the original offset.
 453          */
 454         data->args.offset = filelayout_get_dserver_offset(lseg, offset);
 455
 456         /* Perform an asynchronous write */
 457         status = nfs_initiate_write(ds->ds_clp->cl_rpcclient, data,
 458                                     &filelayout_write_call_ops, sync);
 459         BUG_ON(status != 0);
 460         return PNFS_ATTEMPTED;
 461 }
 462
 463 /*
 464  * filelayout_check_layout()
 465  *
 466  * Make sure layout segment parameters are sane WRT the device.
 467  * At this point no generic layer initialization of the lseg has occurred,
 468  * and nothing has been added to the layout_hdr cache.
 469  *
 470  */
 471 static int
 472 filelayout_check_layout(struct pnfs_layout_hdr *lo,
 473                         struct nfs4_filelayout_segment *fl,
 474                         struct nfs4_layoutget_res *lgr,
 475                         struct nfs4_deviceid *id,
 476                         gfp_t gfp_flags)
 477 {
 478         struct nfs4_deviceid_node *d;
 479         struct nfs4_file_layout_dsaddr *dsaddr;
 480         int status = -EINVAL;
 481         struct nfs_server *nfss = NFS_SERVER(lo->plh_inode);
 482
 483         dprintk("--> %s\n", __func__);
 484
 485         /* FIXME: remove this check when layout segment support is added */
 486         if (lgr->range.offset != 0 ||
 487             lgr->range.length != NFS4_MAX_UINT64) {
 488                 dprintk("%s Only whole file layouts supported. Use MDS i/o\n",
 489                         __func__);
 490                 goto out;
 491         }
 492
 493         if (fl->pattern_offset > lgr->range.offset) {
 494                 dprintk("%s pattern_offset %lld too large\n",
 495                                 __func__, fl->pattern_offset);
 496                 goto out;
 497         }
 498
 499         if (!fl->stripe_unit || fl->stripe_unit % PAGE_SIZE) {
 500                 dprintk("%s Invalid stripe unit (%u)\n",
 501                         __func__, fl->stripe_unit);
 502                 goto out;
 503         }
 504
 505         /* find and reference the deviceid */
 506         d = nfs4_find_get_deviceid(NFS_SERVER(lo->plh_inode)->pnfs_curr_ld,
 507                                    NFS_SERVER(lo->plh_inode)->nfs_client, id);
 508         if (d == NULL) {
 509                 dsaddr = get_device_info(lo->plh_inode, id, gfp_flags);
 510                 if (dsaddr == NULL)
 511                         goto out;
 512         } else
 513                 dsaddr = container_of(d, struct nfs4_file_layout_dsaddr, id_node);
 514         /* Found deviceid is being reaped */
 515         if (test_bit(NFS_DEVICEID_INVALID, &dsaddr->id_node.flags))
 516                         goto out_put;
 517
 518         fl->dsaddr = dsaddr;
 519
 520         if (fl->first_stripe_index >= dsaddr->stripe_count) {
 521                 dprintk("%s Bad first_stripe_index %u\n",
 522                                 __func__, fl->first_stripe_index);
 523                 goto out_put;
 524         }
 525
 526         if ((fl->stripe_type == STRIPE_SPARSE &&
 527             fl->num_fh > 1 && fl->num_fh != dsaddr->ds_num) ||
 528             (fl->stripe_type == STRIPE_DENSE &&
 529             fl->num_fh != dsaddr->stripe_count)) {
 530                 dprintk("%s num_fh %u not valid for given packing\n",
 531                         __func__, fl->num_fh);
 532                 goto out_put;
 533         }
 534
 535         if (fl->stripe_unit % nfss->rsize || fl->stripe_unit % nfss->wsize) {
 536                 dprintk("%s Stripe unit (%u) not aligned with rsize %u "
 537                         "wsize %u\n", __func__, fl->stripe_unit, nfss->rsize,
 538                         nfss->wsize);
 539         }
 540
 541         status = 0;
 542 out:
 543         dprintk("--> %s returns %d\n", __func__, status);
 544         return status;
 545 out_put:
 546         nfs4_fl_put_deviceid(dsaddr);
 547         goto out;
 548 }
 549
 550 static void filelayout_free_fh_array(struct nfs4_filelayout_segment *fl)
 551 {
 552         int i;
 553
 554         for (i = 0; i < fl->num_fh; i++) {
 555                 if (!fl->fh_array[i])
 556                         break;
 557                 kfree(fl->fh_array[i]);
 558         }
 559         kfree(fl->fh_array);
 560         fl->fh_array = NULL;
 561 }
 562
 563 static void
 564 _filelayout_free_lseg(struct nfs4_filelayout_segment *fl)
 565 {
 566         filelayout_free_fh_array(fl);
 567         kfree(fl);
 568 }
 569
 570 static int
 571 filelayout_decode_layout(struct pnfs_layout_hdr *flo,
 572                          struct nfs4_filelayout_segment *fl,
 573                          struct nfs4_layoutget_res *lgr,
 574                          struct nfs4_deviceid *id,
 575                          gfp_t gfp_flags)
 576 {
 577         struct xdr_stream stream;
 578         struct xdr_buf buf;
 579         struct page *scratch;
 580         __be32 *p;
 581         uint32_t nfl_util;
 582         int i;
 583
 584         dprintk("%s: set_layout_map Begin\n", __func__);
 585
 586         scratch = alloc_page(gfp_flags);
 587         if (!scratch)
 588                 return -ENOMEM;
 589
 590         xdr_init_decode_pages(&stream, &buf, lgr->layoutp->pages, lgr->layoutp->len);
 591         xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
 592
 593         /* 20 = ufl_util (4), first_stripe_index (4), pattern_offset (8),
 594          * num_fh (4) */
 595         p = xdr_inline_decode(&stream, NFS4_DEVICEID4_SIZE + 20);
 596         if (unlikely(!p))
 597                 goto out_err;
 598
 599         memcpy(id, p, sizeof(*id));
 600         p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);
 601         nfs4_print_deviceid(id);
 602
 603         nfl_util = be32_to_cpup(p++);
 604         if (nfl_util & NFL4_UFLG_COMMIT_THRU_MDS)
 605                 fl->commit_through_mds = 1;
 606         if (nfl_util & NFL4_UFLG_DENSE)
 607                 fl->stripe_type = STRIPE_DENSE;
 608         else
 609                 fl->stripe_type = STRIPE_SPARSE;
 610         fl->stripe_unit = nfl_util & ~NFL4_UFLG_MASK;
 611
 612         fl->first_stripe_index = be32_to_cpup(p++);
 613         p = xdr_decode_hyper(p, &fl->pattern_offset);
 614         fl->num_fh = be32_to_cpup(p++);
 615
 616         dprintk("%s: nfl_util 0x%X num_fh %u fsi %u po %llu\n",
 617                 __func__, nfl_util, fl->num_fh, fl->first_stripe_index,
 618                 fl->pattern_offset);
 619
 620         /* Note that a zero value for num_fh is legal for STRIPE_SPARSE.
 621          * Futher checking is done in filelayout_check_layout */
 622         if (fl->num_fh >
 623             max(NFS4_PNFS_MAX_STRIPE_CNT, NFS4_PNFS_MAX_MULTI_CNT))
 624                 goto out_err;
 625
 626         if (fl->num_fh > 0) {
 627                 fl->fh_array = kzalloc(fl->num_fh * sizeof(struct nfs_fh *),
 628                                        gfp_flags);
 629                 if (!fl->fh_array)
 630                         goto out_err;
 631         }
 632
 633         for (i = 0; i < fl->num_fh; i++) {
 634                 /* Do we want to use a mempool here? */
 635                 fl->fh_array[i] = kmalloc(sizeof(struct nfs_fh), gfp_flags);
 636                 if (!fl->fh_array[i])
 637                         goto out_err_free;
 638
 639                 p = xdr_inline_decode(&stream, 4);
 640                 if (unlikely(!p))
 641                         goto out_err_free;
 642                 fl->fh_array[i]->size = be32_to_cpup(p++);
 643                 if (sizeof(struct nfs_fh) < fl->fh_array[i]->size) {
 644                         printk(KERN_ERR "NFS: Too big fh %d received %d\n",
 645                                i, fl->fh_array[i]->size);
 646                         goto out_err_free;
 647                 }
 648
 649                 p = xdr_inline_decode(&stream, fl->fh_array[i]->size);
 650                 if (unlikely(!p))
 651                         goto out_err_free;
 652                 memcpy(fl->fh_array[i]->data, p, fl->fh_array[i]->size);
 653                 dprintk("DEBUG: %s: fh len %d\n", __func__,
 654                         fl->fh_array[i]->size);
 655         }
 656
 657         __free_page(scratch);
 658         return 0;
 659
 660 out_err_free:
 661         filelayout_free_fh_array(fl);
 662 out_err:
 663         __free_page(scratch);
 664         return -EIO;
 665 }
 666
 667 static void
 668 filelayout_free_lseg(struct pnfs_layout_segment *lseg)
 669 {
 670         struct nfs4_filelayout_segment *fl = FILELAYOUT_LSEG(lseg);
 671
 672         dprintk("--> %s\n", __func__);
 673         nfs4_fl_put_deviceid(fl->dsaddr);
 674         /* This assumes a single RW lseg */
 675         if (lseg->pls_range.iomode == IOMODE_RW) {
 676                 struct nfs4_filelayout *flo;
 677
 678                 flo = FILELAYOUT_FROM_HDR(lseg->pls_layout);
 679                 flo->commit_info.nbuckets = 0;
 680                 kfree(flo->commit_info.buckets);
 681                 flo->commit_info.buckets = NULL;
 682         }
 683         _filelayout_free_lseg(fl);
 684 }
 685
 686 static int
 687 filelayout_alloc_commit_info(struct pnfs_layout_segment *lseg,
 688                              struct nfs_commit_info *cinfo,
 689                              gfp_t gfp_flags)
 690 {
 691         struct nfs4_filelayout_segment *fl = FILELAYOUT_LSEG(lseg);
 692         struct pnfs_commit_bucket *buckets;
 693         int size;
 694
 695         if (fl->commit_through_mds)
 696                 return 0;
 697         if (cinfo->ds->nbuckets != 0) {
 698                 /* This assumes there is only one IOMODE_RW lseg.  What
 699                  * we really want to do is have a layout_hdr level
 700                  * dictionary of <multipath_list4, fh> keys, each
 701                  * associated with a struct list_head, populated by calls
 702                  * to filelayout_write_pagelist().
 703                  * */
 704                 return 0;
 705         }
 706
 707         size = (fl->stripe_type == STRIPE_SPARSE) ?
 708                 fl->dsaddr->ds_num : fl->dsaddr->stripe_count;
 709
 710         buckets = kcalloc(size, sizeof(struct pnfs_commit_bucket),
 711                           gfp_flags);
 712         if (!buckets)
 713                 return -ENOMEM;
 714         else {
 715                 int i;
 716
 717                 spin_lock(cinfo->lock);
 718                 if (cinfo->ds->nbuckets != 0)
 719                         kfree(buckets);
 720                 else {
 721                         cinfo->ds->buckets = buckets;
 722                         cinfo->ds->nbuckets = size;
 723                         for (i = 0; i < size; i++) {
 724                                 INIT_LIST_HEAD(&buckets[i].written);
 725                                 INIT_LIST_HEAD(&buckets[i].committing);
 726                         }
 727                 }
 728                 spin_unlock(cinfo->lock);
 729                 return 0;
 730         }
 731 }
 732
 733 static struct pnfs_layout_segment *
 734 filelayout_alloc_lseg(struct pnfs_layout_hdr *layoutid,
 735                       struct nfs4_layoutget_res *lgr,
 736                       gfp_t gfp_flags)
 737 {
 738         struct nfs4_filelayout_segment *fl;
 739         int rc;
 740         struct nfs4_deviceid id;
 741
 742         dprintk("--> %s\n", __func__);
 743         fl = kzalloc(sizeof(*fl), gfp_flags);
 744         if (!fl)
 745                 return NULL;
 746
 747         rc = filelayout_decode_layout(layoutid, fl, lgr, &id, gfp_flags);
 748         if (rc != 0 || filelayout_check_layout(layoutid, fl, lgr, &id, gfp_flags)) {
 749                 _filelayout_free_lseg(fl);
 750                 return NULL;
 751         }
 752         return &fl->generic_hdr;
 753 }
 754
 755 /*
 756  * filelayout_pg_test(). Called by nfs_can_coalesce_requests()
 757  *
 758  * return true  : coalesce page
 759  * return false : don't coalesce page
 760  */
 761 static bool
 762 filelayout_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
 763                    struct nfs_page *req)
 764 {
 765         u64 p_stripe, r_stripe;
 766         u32 stripe_unit;
 767
 768         if (!pnfs_generic_pg_test(pgio, prev, req) ||
 769             !nfs_generic_pg_test(pgio, prev, req))
 770                 return false;
 771
 772         p_stripe = (u64)req_offset(prev);
 773         r_stripe = (u64)req_offset(req);
 774         stripe_unit = FILELAYOUT_LSEG(pgio->pg_lseg)->stripe_unit;
 775
 776         do_div(p_stripe, stripe_unit);
 777         do_div(r_stripe, stripe_unit);
 778
 779         return (p_stripe == r_stripe);
 780 }
 781
 782 static void
 783 filelayout_pg_init_read(struct nfs_pageio_descriptor *pgio,
 784                         struct nfs_page *req)
 785 {
 786         BUG_ON(pgio->pg_lseg != NULL);
 787
 788         if (req->wb_offset != req->wb_pgbase) {
 789                 /*
 790                  * Handling unaligned pages is difficult, because have to
 791                  * somehow split a req in two in certain cases in the
 792                  * pg.test code.  Avoid this by just not using pnfs
 793                  * in this case.
 794                  */
 795                 nfs_pageio_reset_read_mds(pgio);
 796                 return;
 797         }
 798         pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
 799                                            req->wb_context,
 800                                            0,
 801                                            NFS4_MAX_UINT64,
 802                                            IOMODE_READ,
 803                                            GFP_KERNEL);
 804         /* If no lseg, fall back to read through mds */
 805         if (pgio->pg_lseg == NULL)
 806                 nfs_pageio_reset_read_mds(pgio);
 807 }
 808
 809 static void
 810 filelayout_pg_init_write(struct nfs_pageio_descriptor *pgio,
 811                          struct nfs_page *req)
 812 {
 813         struct nfs_commit_info cinfo;
 814         int status;
 815
 816         BUG_ON(pgio->pg_lseg != NULL);
 817
 818         if (req->wb_offset != req->wb_pgbase)
 819                 goto out_mds;
 820         pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
 821                                            req->wb_context,
 822                                            0,
 823                                            NFS4_MAX_UINT64,
 824                                            IOMODE_RW,
 825                                            GFP_NOFS);
 826         /* If no lseg, fall back to write through mds */
 827         if (pgio->pg_lseg == NULL)
 828                 goto out_mds;
 829         nfs_init_cinfo(&cinfo, pgio->pg_inode, pgio->pg_dreq);
 830         status = filelayout_alloc_commit_info(pgio->pg_lseg, &cinfo, GFP_NOFS);
 831         if (status < 0) {
 832                 put_lseg(pgio->pg_lseg);
 833                 pgio->pg_lseg = NULL;
 834                 goto out_mds;
 835         }
 836         return;
 837 out_mds:
 838         nfs_pageio_reset_write_mds(pgio);
 839 }
 840
 841 static const struct nfs_pageio_ops filelayout_pg_read_ops = {
 842         .pg_init = filelayout_pg_init_read,
 843         .pg_test = filelayout_pg_test,
 844         .pg_doio = pnfs_generic_pg_readpages,
 845 };
 846
 847 static const struct nfs_pageio_ops filelayout_pg_write_ops = {
 848         .pg_init = filelayout_pg_init_write,
 849         .pg_test = filelayout_pg_test,
 850         .pg_doio = pnfs_generic_pg_writepages,
 851 };
 852
 853 static u32 select_bucket_index(struct nfs4_filelayout_segment *fl, u32 j)
 854 {
 855         if (fl->stripe_type == STRIPE_SPARSE)
 856                 return nfs4_fl_calc_ds_index(&fl->generic_hdr, j);
 857         else
 858                 return j;
 859 }
 860
 861 /* The generic layer is about to remove the req from the commit list.
 862  * If this will make the bucket empty, it will need to put the lseg reference.
 863  */
 864 static void
 865 filelayout_clear_request_commit(struct nfs_page *req,
 866                                 struct nfs_commit_info *cinfo)
 867 {
 868         struct pnfs_layout_segment *freeme = NULL;
 869
 870         spin_lock(cinfo->lock);
 871         if (!test_and_clear_bit(PG_COMMIT_TO_DS, &req->wb_flags))
 872                 goto out;
 873         cinfo->ds->nwritten--;
 874         if (list_is_singular(&req->wb_list)) {
 875                 struct pnfs_commit_bucket *bucket;
 876
 877                 bucket = list_first_entry(&req->wb_list,
 878                                           struct pnfs_commit_bucket,
 879                                           written);
 880                 freeme = bucket->wlseg;
 881                 bucket->wlseg = NULL;
 882         }
 883 out:
 884         nfs_request_remove_commit_list(req, cinfo);
 885         spin_unlock(cinfo->lock);
 886         put_lseg(freeme);
 887 }
 888
 889 static struct list_head *
 890 filelayout_choose_commit_list(struct nfs_page *req,
 891                               struct pnfs_layout_segment *lseg,
 892                               struct nfs_commit_info *cinfo)
 893 {
 894         struct nfs4_filelayout_segment *fl = FILELAYOUT_LSEG(lseg);
 895         u32 i, j;
 896         struct list_head *list;
 897         struct pnfs_commit_bucket *buckets;
 898
 899         if (fl->commit_through_mds)
 900                 return &cinfo->mds->list;
 901
 902         /* Note that we are calling nfs4_fl_calc_j_index on each page
 903          * that ends up being committed to a data server.  An attractive
 904          * alternative is to add a field to nfs_write_data and nfs_page
 905          * to store the value calculated in filelayout_write_pagelist
 906          * and just use that here.
 907          */
 908         j = nfs4_fl_calc_j_index(lseg, req_offset(req));
 909         i = select_bucket_index(fl, j);
 910         buckets = cinfo->ds->buckets;
 911         list = &buckets[i].written;
 912         if (list_empty(list)) {
 913                 /* Non-empty buckets hold a reference on the lseg.  That ref
 914                  * is normally transferred to the COMMIT call and released
 915                  * there.  It could also be released if the last req is pulled
 916                  * off due to a rewrite, in which case it will be done in
 917                  * filelayout_clear_request_commit
 918                  */
 919                 buckets[i].wlseg = get_lseg(lseg);
 920         }
 921         set_bit(PG_COMMIT_TO_DS, &req->wb_flags);
 922         cinfo->ds->nwritten++;
 923         return list;
 924 }
 925
 926 static void
 927 filelayout_mark_request_commit(struct nfs_page *req,
 928                                struct pnfs_layout_segment *lseg,
 929                                struct nfs_commit_info *cinfo)
 930 {
 931         struct list_head *list;
 932
 933         list = filelayout_choose_commit_list(req, lseg, cinfo);
 934         nfs_request_add_commit_list(req, list, cinfo);
 935 }
 936
 937 static u32 calc_ds_index_from_commit(struct pnfs_layout_segment *lseg, u32 i)
 938 {
 939         struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
 940
 941         if (flseg->stripe_type == STRIPE_SPARSE)
 942                 return i;
 943         else
 944                 return nfs4_fl_calc_ds_index(lseg, i);
 945 }
 946
 947 static struct nfs_fh *
 948 select_ds_fh_from_commit(struct pnfs_layout_segment *lseg, u32 i)
 949 {
 950         struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
 951
 952         if (flseg->stripe_type == STRIPE_SPARSE) {
 953                 if (flseg->num_fh == 1)
 954                         i = 0;
 955                 else if (flseg->num_fh == 0)
 956                         /* Use the MDS OPEN fh set in nfs_read_rpcsetup */
 957                         return NULL;
 958         }
 959         return flseg->fh_array[i];
 960 }
 961
 962 static int filelayout_initiate_commit(struct nfs_commit_data *data, int how)
 963 {
 964         struct pnfs_layout_segment *lseg = data->lseg;
 965         struct nfs4_pnfs_ds *ds;
 966         u32 idx;
 967         struct nfs_fh *fh;
 968
 969         idx = calc_ds_index_from_commit(lseg, data->ds_commit_index);
 970         ds = nfs4_fl_prepare_ds(lseg, idx);
 971         if (!ds) {
 972                 set_bit(lo_fail_bit(IOMODE_RW), &lseg->pls_layout->plh_flags);
 973                 set_bit(lo_fail_bit(IOMODE_READ), &lseg->pls_layout->plh_flags);
 974                 prepare_to_resend_writes(data);
 975                 filelayout_commit_release(data);
 976                 return -EAGAIN;
 977         }
 978         dprintk("%s ino %lu, how %d\n", __func__, data->inode->i_ino, how);
 979         data->commit_done_cb = filelayout_commit_done_cb;
 980         data->ds_clp = ds->ds_clp;
 981         fh = select_ds_fh_from_commit(lseg, data->ds_commit_index);
 982         if (fh)
 983                 data->args.fh = fh;
 984         return nfs_initiate_commit(ds->ds_clp->cl_rpcclient, data,
 985                                    &filelayout_commit_call_ops, how);
 986 }
 987
 988 static int
 989 transfer_commit_list(struct list_head *src, struct list_head *dst,
 990                      struct nfs_commit_info *cinfo, int max)
 991 {
 992         struct nfs_page *req, *tmp;
 993         int ret = 0;
 994
 995         list_for_each_entry_safe(req, tmp, src, wb_list) {
 996                 if (!nfs_lock_request(req))
 997                         continue;
 998                 if (cond_resched_lock(cinfo->lock))
 999                         list_safe_reset_next(req, tmp, wb_list);
1000                 nfs_request_remove_commit_list(req, cinfo);
1001                 clear_bit(PG_COMMIT_TO_DS, &req->wb_flags);
1002                 nfs_list_add_request(req, dst);
1003                 ret++;
1004                 if ((ret == max) && !cinfo->dreq)
1005                         break;
1006         }
1007         return ret;
1008 }
1009
1010 static int
1011 filelayout_scan_ds_commit_list(struct pnfs_commit_bucket *bucket,
1012                                struct nfs_commit_info *cinfo,
1013                                int max)
1014 {
1015         struct list_head *src = &bucket->written;
1016         struct list_head *dst = &bucket->committing;
1017         int ret;
1018
1019         ret = transfer_commit_list(src, dst, cinfo, max);
1020         if (ret) {
1021                 cinfo->ds->nwritten -= ret;
1022                 cinfo->ds->ncommitting += ret;
1023                 bucket->clseg = bucket->wlseg;
1024                 if (list_empty(src))
1025                         bucket->wlseg = NULL;
1026                 else
1027                         get_lseg(bucket->clseg);
1028         }
1029         return ret;
1030 }
1031
1032 /* Move reqs from written to committing lists, returning count of number moved.
1033  * Note called with cinfo->lock held.
1034  */
1035 static int filelayout_scan_commit_lists(struct nfs_commit_info *cinfo,
1036                                         int max)
1037 {
1038         int i, rv = 0, cnt;
1039
1040         for (i = 0; i < cinfo->ds->nbuckets && max != 0; i++) {
1041                 cnt = filelayout_scan_ds_commit_list(&cinfo->ds->buckets[i],
1042                                                      cinfo, max);
1043                 max -= cnt;
1044                 rv += cnt;
1045         }
1046         return rv;
1047 }
1048
1049 /* Pull everything off the committing lists and dump into @dst */
1050 static void filelayout_recover_commit_reqs(struct list_head *dst,
1051                                            struct nfs_commit_info *cinfo)
1052 {
1053         struct pnfs_commit_bucket *b;
1054         int i;
1055
1056         /* NOTE cinfo->lock is NOT held, relying on fact that this is
1057          * only called on single thread per dreq.
1058          * Can't take the lock because need to do put_lseg
1059          */
1060         for (i = 0, b = cinfo->ds->buckets; i < cinfo->ds->nbuckets; i++, b++) {
1061                 if (transfer_commit_list(&b->written, dst, cinfo, 0)) {
1062                         BUG_ON(!list_empty(&b->written));
1063                         put_lseg(b->wlseg);
1064                         b->wlseg = NULL;
1065                 }
1066         }
1067         cinfo->ds->nwritten = 0;
1068 }
1069
1070 static unsigned int
1071 alloc_ds_commits(struct nfs_commit_info *cinfo, struct list_head *list)
1072 {
1073         struct pnfs_ds_commit_info *fl_cinfo;
1074         struct pnfs_commit_bucket *bucket;
1075         struct nfs_commit_data *data;
1076         int i, j;
1077         unsigned int nreq = 0;
1078
1079         fl_cinfo = cinfo->ds;
1080         bucket = fl_cinfo->buckets;
1081         for (i = 0; i < fl_cinfo->nbuckets; i++, bucket++) {
1082                 if (list_empty(&bucket->committing))
1083                         continue;
1084                 data = nfs_commitdata_alloc();
1085                 if (!data)
1086                         break;
1087                 data->ds_commit_index = i;
1088                 data->lseg = bucket->clseg;
1089                 bucket->clseg = NULL;
1090                 list_add(&data->pages, list);
1091                 nreq++;
1092         }
1093
1094         /* Clean up on error */
1095         for (j = i; j < fl_cinfo->nbuckets; j++, bucket++) {
1096                 if (list_empty(&bucket->committing))
1097                         continue;
1098                 nfs_retry_commit(&bucket->committing, bucket->clseg, cinfo);
1099                 put_lseg(bucket->clseg);
1100                 bucket->clseg = NULL;
1101         }
1102         /* Caller will clean up entries put on list */
1103         return nreq;
1104 }
1105
1106 /* This follows nfs_commit_list pretty closely */
1107 static int
1108 filelayout_commit_pagelist(struct inode *inode, struct list_head *mds_pages,
1109                            int how, struct nfs_commit_info *cinfo)
1110 {
1111         struct nfs_commit_data *data, *tmp;
1112         LIST_HEAD(list);
1113         unsigned int nreq = 0;
1114
1115         if (!list_empty(mds_pages)) {
1116                 data = nfs_commitdata_alloc();
1117                 if (data != NULL) {
1118                         data->lseg = NULL;
1119                         list_add(&data->pages, &list);
1120                         nreq++;
1121                 } else
1122                         nfs_retry_commit(mds_pages, NULL, cinfo);
1123         }
1124
1125         nreq += alloc_ds_commits(cinfo, &list);
1126
1127         if (nreq == 0) {
1128                 cinfo->completion_ops->error_cleanup(NFS_I(inode));
1129                 goto out;
1130         }
1131
1132         atomic_add(nreq, &cinfo->mds->rpcs_out);
1133
1134         list_for_each_entry_safe(data, tmp, &list, pages) {
1135                 list_del_init(&data->pages);
1136                 if (!data->lseg) {
1137                         nfs_init_commit(data, mds_pages, NULL, cinfo);
1138                         nfs_initiate_commit(NFS_CLIENT(inode), data,
1139                                             data->mds_ops, how);
1140                 } else {
1141                         struct pnfs_commit_bucket *buckets;
1142
1143                         buckets = cinfo->ds->buckets;
1144                         nfs_init_commit(data, &buckets[data->ds_commit_index].committing, data->lseg, cinfo);
1145                         filelayout_initiate_commit(data, how);
1146                 }
1147         }
1148 out:
1149         cinfo->ds->ncommitting = 0;
1150         return PNFS_ATTEMPTED;
1151 }
1152
1153 static void
1154 filelayout_free_deveiceid_node(struct nfs4_deviceid_node *d)
1155 {
1156         nfs4_fl_free_deviceid(container_of(d, struct nfs4_file_layout_dsaddr, id_node));
1157 }
1158
1159 static struct pnfs_layout_hdr *
1160 filelayout_alloc_layout_hdr(struct inode *inode, gfp_t gfp_flags)
1161 {
1162         struct nfs4_filelayout *flo;
1163
1164         flo = kzalloc(sizeof(*flo), gfp_flags);
1165         return &flo->generic_hdr;
1166 }
1167
1168 static void
1169 filelayout_free_layout_hdr(struct pnfs_layout_hdr *lo)
1170 {
1171         kfree(FILELAYOUT_FROM_HDR(lo));
1172 }
1173
1174 static struct pnfs_ds_commit_info *
1175 filelayout_get_ds_info(struct inode *inode)
1176 {
1177         struct pnfs_layout_hdr *layout = NFS_I(inode)->layout;
1178
1179         if (layout == NULL)
1180                 return NULL;
1181         else
1182                 return &FILELAYOUT_FROM_HDR(layout)->commit_info;
1183 }
1184
1185 static struct pnfs_layoutdriver_type filelayout_type = {
1186         .id                     = LAYOUT_NFSV4_1_FILES,
1187         .name                   = "LAYOUT_NFSV4_1_FILES",
1188         .owner                  = THIS_MODULE,
1189         .alloc_layout_hdr       = filelayout_alloc_layout_hdr,
1190         .free_layout_hdr        = filelayout_free_layout_hdr,
1191         .alloc_lseg             = filelayout_alloc_lseg,
1192         .free_lseg              = filelayout_free_lseg,
1193         .pg_read_ops            = &filelayout_pg_read_ops,
1194         .pg_write_ops           = &filelayout_pg_write_ops,
1195         .get_ds_info            = &filelayout_get_ds_info,
1196         .mark_request_commit    = filelayout_mark_request_commit,
1197         .clear_request_commit   = filelayout_clear_request_commit,
1198         .scan_commit_lists      = filelayout_scan_commit_lists,
1199         .recover_commit_reqs    = filelayout_recover_commit_reqs,
1200         .commit_pagelist        = filelayout_commit_pagelist,
1201         .read_pagelist          = filelayout_read_pagelist,
1202         .write_pagelist         = filelayout_write_pagelist,
1203         .free_deviceid_node     = filelayout_free_deveiceid_node,
1204 };
1205
1206 static int __init nfs4filelayout_init(void)
1207 {
1208         printk(KERN_INFO "%s: NFSv4 File Layout Driver Registering...\n",
1209                __func__);
1210         return pnfs_register_layoutdriver(&filelayout_type);
1211 }
1212
1213 static void __exit nfs4filelayout_exit(void)
1214 {
1215         printk(KERN_INFO "%s: NFSv4 File Layout Driver Unregistering...\n",
1216                __func__);
1217         pnfs_unregister_layoutdriver(&filelayout_type);
1218 }
1219
1220 MODULE_ALIAS("nfs-layouttype4-1");
1221
1222 module_init(nfs4filelayout_init);
1223 module_exit(nfs4filelayout_exit);