fs/nfs/filelayout/filelayout.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 #include <linux/backing-dev.h>
  36
  37 #include <linux/sunrpc/metrics.h>
  38
  39 #include "../nfs4session.h"
  40 #include "../internal.h"
  41 #include "../delegation.h"
  42 #include "filelayout.h"
  43 #include "../nfs4trace.h"
  44
  45 #define NFSDBG_FACILITY         NFSDBG_PNFS_LD
  46
  47 MODULE_LICENSE("GPL");
  48 MODULE_AUTHOR("Dean Hildebrand <dhildebz@umich.edu>");
  49 MODULE_DESCRIPTION("The NFSv4 file layout driver");
  50
  51 #define FILELAYOUT_POLL_RETRY_MAX     (15*HZ)
  52
  53 static loff_t
  54 filelayout_get_dense_offset(struct nfs4_filelayout_segment *flseg,
  55                             loff_t offset)
  56 {
  57         u32 stripe_width = flseg->stripe_unit * flseg->dsaddr->stripe_count;
  58         u64 stripe_no;
  59         u32 rem;
  60
  61         offset -= flseg->pattern_offset;
  62         stripe_no = div_u64(offset, stripe_width);
  63         div_u64_rem(offset, flseg->stripe_unit, &rem);
  64
  65         return stripe_no * flseg->stripe_unit + rem;
  66 }
  67
  68 /* This function is used by the layout driver to calculate the
  69  * offset of the file on the dserver based on whether the
  70  * layout type is STRIPE_DENSE or STRIPE_SPARSE
  71  */
  72 static loff_t
  73 filelayout_get_dserver_offset(struct pnfs_layout_segment *lseg, loff_t offset)
  74 {
  75         struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
  76
  77         switch (flseg->stripe_type) {
  78         case STRIPE_SPARSE:
  79                 return offset;
  80
  81         case STRIPE_DENSE:
  82                 return filelayout_get_dense_offset(flseg, offset);
  83         }
  84
  85         BUG();
  86 }
  87
  88 static void filelayout_reset_write(struct nfs_pgio_header *hdr)
  89 {
  90         struct rpc_task *task = &hdr->task;
  91
  92         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
  93                 dprintk("%s Reset task %5u for i/o through MDS "
  94                         "(req %s/%llu, %u bytes @ offset %llu)\n", __func__,
  95                         hdr->task.tk_pid,
  96                         hdr->inode->i_sb->s_id,
  97                         (unsigned long long)NFS_FILEID(hdr->inode),
  98                         hdr->args.count,
  99                         (unsigned long long)hdr->args.offset);
 100
 101                 task->tk_status = pnfs_write_done_resend_to_mds(hdr);
 102         }
 103 }
 104
 105 static void filelayout_reset_read(struct nfs_pgio_header *hdr)
 106 {
 107         struct rpc_task *task = &hdr->task;
 108
 109         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
 110                 dprintk("%s Reset task %5u for i/o through MDS "
 111                         "(req %s/%llu, %u bytes @ offset %llu)\n", __func__,
 112                         hdr->task.tk_pid,
 113                         hdr->inode->i_sb->s_id,
 114                         (unsigned long long)NFS_FILEID(hdr->inode),
 115                         hdr->args.count,
 116                         (unsigned long long)hdr->args.offset);
 117
 118                 task->tk_status = pnfs_read_done_resend_to_mds(hdr);
 119         }
 120 }
 121
 122 static int filelayout_async_handle_error(struct rpc_task *task,
 123                                          struct nfs4_state *state,
 124                                          struct nfs_client *clp,
 125                                          struct pnfs_layout_segment *lseg)
 126 {
 127         struct pnfs_layout_hdr *lo = lseg->pls_layout;
 128         struct inode *inode = lo->plh_inode;
 129         struct nfs_server *mds_server = NFS_SERVER(inode);
 130         struct nfs4_deviceid_node *devid = FILELAYOUT_DEVID_NODE(lseg);
 131         struct nfs_client *mds_client = mds_server->nfs_client;
 132         struct nfs4_slot_table *tbl = &clp->cl_session->fc_slot_table;
 133
 134         if (task->tk_status >= 0)
 135                 return 0;
 136
 137         switch (task->tk_status) {
 138         /* MDS state errors */
 139         case -NFS4ERR_DELEG_REVOKED:
 140         case -NFS4ERR_ADMIN_REVOKED:
 141         case -NFS4ERR_BAD_STATEID:
 142         case -NFS4ERR_OPENMODE:
 143                 if (state == NULL)
 144                         break;
 145                 if (nfs4_schedule_stateid_recovery(mds_server, state) < 0)
 146                         goto out_bad_stateid;
 147                 goto wait_on_recovery;
 148         case -NFS4ERR_EXPIRED:
 149                 if (state != NULL) {
 150                         if (nfs4_schedule_stateid_recovery(mds_server, state) < 0)
 151                                 goto out_bad_stateid;
 152                 }
 153                 nfs4_schedule_lease_recovery(mds_client);
 154                 goto wait_on_recovery;
 155         /* DS session errors */
 156         case -NFS4ERR_BADSESSION:
 157         case -NFS4ERR_BADSLOT:
 158         case -NFS4ERR_BAD_HIGH_SLOT:
 159         case -NFS4ERR_DEADSESSION:
 160         case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
 161         case -NFS4ERR_SEQ_FALSE_RETRY:
 162         case -NFS4ERR_SEQ_MISORDERED:
 163                 dprintk("%s ERROR %d, Reset session. Exchangeid "
 164                         "flags 0x%x\n", __func__, task->tk_status,
 165                         clp->cl_exchange_flags);
 166                 nfs4_schedule_session_recovery(clp->cl_session, task->tk_status);
 167                 break;
 168         case -NFS4ERR_DELAY:
 169         case -NFS4ERR_GRACE:
 170                 rpc_delay(task, FILELAYOUT_POLL_RETRY_MAX);
 171                 break;
 172         case -NFS4ERR_RETRY_UNCACHED_REP:
 173                 break;
 174         /* Invalidate Layout errors */
 175         case -NFS4ERR_PNFS_NO_LAYOUT:
 176         case -ESTALE:           /* mapped NFS4ERR_STALE */
 177         case -EBADHANDLE:       /* mapped NFS4ERR_BADHANDLE */
 178         case -EISDIR:           /* mapped NFS4ERR_ISDIR */
 179         case -NFS4ERR_FHEXPIRED:
 180         case -NFS4ERR_WRONG_TYPE:
 181                 dprintk("%s Invalid layout error %d\n", __func__,
 182                         task->tk_status);
 183                 /*
 184                  * Destroy layout so new i/o will get a new layout.
 185                  * Layout will not be destroyed until all current lseg
 186                  * references are put. Mark layout as invalid to resend failed
 187                  * i/o and all i/o waiting on the slot table to the MDS until
 188                  * layout is destroyed and a new valid layout is obtained.
 189                  */
 190                 pnfs_destroy_layout(NFS_I(inode));
 191                 rpc_wake_up(&tbl->slot_tbl_waitq);
 192                 goto reset;
 193         /* RPC connection errors */
 194         case -ECONNREFUSED:
 195         case -EHOSTDOWN:
 196         case -EHOSTUNREACH:
 197         case -ENETUNREACH:
 198         case -EIO:
 199         case -ETIMEDOUT:
 200         case -EPIPE:
 201                 dprintk("%s DS connection error %d\n", __func__,
 202                         task->tk_status);
 203                 nfs4_mark_deviceid_unavailable(devid);
 204                 pnfs_error_mark_layout_for_return(inode, lseg);
 205                 pnfs_set_lo_fail(lseg);
 206                 rpc_wake_up(&tbl->slot_tbl_waitq);
 207                 /* fall through */
 208         default:
 209 reset:
 210                 dprintk("%s Retry through MDS. Error %d\n", __func__,
 211                         task->tk_status);
 212                 return -NFS4ERR_RESET_TO_MDS;
 213         }
 214 out:
 215         task->tk_status = 0;
 216         return -EAGAIN;
 217 out_bad_stateid:
 218         task->tk_status = -EIO;
 219         return 0;
 220 wait_on_recovery:
 221         rpc_sleep_on(&mds_client->cl_rpcwaitq, task, NULL);
 222         if (test_bit(NFS4CLNT_MANAGER_RUNNING, &mds_client->cl_state) == 0)
 223                 rpc_wake_up_queued_task(&mds_client->cl_rpcwaitq, task);
 224         goto out;
 225 }
 226
 227 /* NFS_PROTO call done callback routines */
 228
 229 static int filelayout_read_done_cb(struct rpc_task *task,
 230                                 struct nfs_pgio_header *hdr)
 231 {
 232         int err;
 233
 234         trace_nfs4_pnfs_read(hdr, task->tk_status);
 235         err = filelayout_async_handle_error(task, hdr->args.context->state,
 236                                             hdr->ds_clp, hdr->lseg);
 237
 238         switch (err) {
 239         case -NFS4ERR_RESET_TO_MDS:
 240                 filelayout_reset_read(hdr);
 241                 return task->tk_status;
 242         case -EAGAIN:
 243                 rpc_restart_call_prepare(task);
 244                 return -EAGAIN;
 245         }
 246
 247         return 0;
 248 }
 249
 250 /*
 251  * We reference the rpc_cred of the first WRITE that triggers the need for
 252  * a LAYOUTCOMMIT, and use it to send the layoutcommit compound.
 253  * rfc5661 is not clear about which credential should be used.
 254  */
 255 static void
 256 filelayout_set_layoutcommit(struct nfs_pgio_header *hdr)
 257 {
 258
 259         if (FILELAYOUT_LSEG(hdr->lseg)->commit_through_mds ||
 260             hdr->res.verf->committed != NFS_DATA_SYNC)
 261                 return;
 262
 263         pnfs_set_layoutcommit(hdr->inode, hdr->lseg,
 264                         hdr->mds_offset + hdr->res.count);
 265         dprintk("%s inode %lu pls_end_pos %lu\n", __func__, hdr->inode->i_ino,
 266                 (unsigned long) NFS_I(hdr->inode)->layout->plh_lwb);
 267 }
 268
 269 bool
 270 filelayout_test_devid_unavailable(struct nfs4_deviceid_node *node)
 271 {
 272         return filelayout_test_devid_invalid(node) ||
 273                 nfs4_test_deviceid_unavailable(node);
 274 }
 275
 276 static bool
 277 filelayout_reset_to_mds(struct pnfs_layout_segment *lseg)
 278 {
 279         struct nfs4_deviceid_node *node = FILELAYOUT_DEVID_NODE(lseg);
 280
 281         return filelayout_test_devid_unavailable(node);
 282 }
 283
 284 /*
 285  * Call ops for the async read/write cases
 286  * In the case of dense layouts, the offset needs to be reset to its
 287  * original value.
 288  */
 289 static void filelayout_read_prepare(struct rpc_task *task, void *data)
 290 {
 291         struct nfs_pgio_header *hdr = data;
 292
 293         if (unlikely(test_bit(NFS_CONTEXT_BAD, &hdr->args.context->flags))) {
 294                 rpc_exit(task, -EIO);
 295                 return;
 296         }
 297         if (filelayout_reset_to_mds(hdr->lseg)) {
 298                 dprintk("%s task %u reset io to MDS\n", __func__, task->tk_pid);
 299                 filelayout_reset_read(hdr);
 300                 rpc_exit(task, 0);
 301                 return;
 302         }
 303         hdr->pgio_done_cb = filelayout_read_done_cb;
 304
 305         if (nfs41_setup_sequence(hdr->ds_clp->cl_session,
 306                         &hdr->args.seq_args,
 307                         &hdr->res.seq_res,
 308                         task))
 309                 return;
 310         if (nfs4_set_rw_stateid(&hdr->args.stateid, hdr->args.context,
 311                         hdr->args.lock_context, FMODE_READ) == -EIO)
 312                 rpc_exit(task, -EIO); /* lost lock, terminate I/O */
 313 }
 314
 315 static void filelayout_read_call_done(struct rpc_task *task, void *data)
 316 {
 317         struct nfs_pgio_header *hdr = data;
 318
 319         dprintk("--> %s task->tk_status %d\n", __func__, task->tk_status);
 320
 321         if (test_bit(NFS_IOHDR_REDO, &hdr->flags) &&
 322             task->tk_status == 0) {
 323                 nfs41_sequence_done(task, &hdr->res.seq_res);
 324                 return;
 325         }
 326
 327         /* Note this may cause RPC to be resent */
 328         hdr->mds_ops->rpc_call_done(task, data);
 329 }
 330
 331 static void filelayout_read_count_stats(struct rpc_task *task, void *data)
 332 {
 333         struct nfs_pgio_header *hdr = data;
 334
 335         rpc_count_iostats(task, NFS_SERVER(hdr->inode)->client->cl_metrics);
 336 }
 337
 338 static int filelayout_write_done_cb(struct rpc_task *task,
 339                                 struct nfs_pgio_header *hdr)
 340 {
 341         int err;
 342
 343         trace_nfs4_pnfs_write(hdr, task->tk_status);
 344         err = filelayout_async_handle_error(task, hdr->args.context->state,
 345                                             hdr->ds_clp, hdr->lseg);
 346
 347         switch (err) {
 348         case -NFS4ERR_RESET_TO_MDS:
 349                 filelayout_reset_write(hdr);
 350                 return task->tk_status;
 351         case -EAGAIN:
 352                 rpc_restart_call_prepare(task);
 353                 return -EAGAIN;
 354         }
 355
 356         filelayout_set_layoutcommit(hdr);
 357         return 0;
 358 }
 359
 360 static int filelayout_commit_done_cb(struct rpc_task *task,
 361                                      struct nfs_commit_data *data)
 362 {
 363         int err;
 364
 365         trace_nfs4_pnfs_commit_ds(data, task->tk_status);
 366         err = filelayout_async_handle_error(task, NULL, data->ds_clp,
 367                                             data->lseg);
 368
 369         switch (err) {
 370         case -NFS4ERR_RESET_TO_MDS:
 371                 pnfs_generic_prepare_to_resend_writes(data);
 372                 return -EAGAIN;
 373         case -EAGAIN:
 374                 rpc_restart_call_prepare(task);
 375                 return -EAGAIN;
 376         }
 377
 378         if (data->verf.committed == NFS_UNSTABLE)
 379                 pnfs_set_layoutcommit(data->inode, data->lseg, data->lwb);
 380
 381         return 0;
 382 }
 383
 384 static void filelayout_write_prepare(struct rpc_task *task, void *data)
 385 {
 386         struct nfs_pgio_header *hdr = data;
 387
 388         if (unlikely(test_bit(NFS_CONTEXT_BAD, &hdr->args.context->flags))) {
 389                 rpc_exit(task, -EIO);
 390                 return;
 391         }
 392         if (filelayout_reset_to_mds(hdr->lseg)) {
 393                 dprintk("%s task %u reset io to MDS\n", __func__, task->tk_pid);
 394                 filelayout_reset_write(hdr);
 395                 rpc_exit(task, 0);
 396                 return;
 397         }
 398         if (nfs41_setup_sequence(hdr->ds_clp->cl_session,
 399                         &hdr->args.seq_args,
 400                         &hdr->res.seq_res,
 401                         task))
 402                 return;
 403         if (nfs4_set_rw_stateid(&hdr->args.stateid, hdr->args.context,
 404                         hdr->args.lock_context, FMODE_WRITE) == -EIO)
 405                 rpc_exit(task, -EIO); /* lost lock, terminate I/O */
 406 }
 407
 408 static void filelayout_write_call_done(struct rpc_task *task, void *data)
 409 {
 410         struct nfs_pgio_header *hdr = data;
 411
 412         if (test_bit(NFS_IOHDR_REDO, &hdr->flags) &&
 413             task->tk_status == 0) {
 414                 nfs41_sequence_done(task, &hdr->res.seq_res);
 415                 return;
 416         }
 417
 418         /* Note this may cause RPC to be resent */
 419         hdr->mds_ops->rpc_call_done(task, data);
 420 }
 421
 422 static void filelayout_write_count_stats(struct rpc_task *task, void *data)
 423 {
 424         struct nfs_pgio_header *hdr = data;
 425
 426         rpc_count_iostats(task, NFS_SERVER(hdr->inode)->client->cl_metrics);
 427 }
 428
 429 static void filelayout_commit_prepare(struct rpc_task *task, void *data)
 430 {
 431         struct nfs_commit_data *wdata = data;
 432
 433         nfs41_setup_sequence(wdata->ds_clp->cl_session,
 434                         &wdata->args.seq_args,
 435                         &wdata->res.seq_res,
 436                         task);
 437 }
 438
 439 static void filelayout_commit_count_stats(struct rpc_task *task, void *data)
 440 {
 441         struct nfs_commit_data *cdata = data;
 442
 443         rpc_count_iostats(task, NFS_SERVER(cdata->inode)->client->cl_metrics);
 444 }
 445
 446 static const struct rpc_call_ops filelayout_read_call_ops = {
 447         .rpc_call_prepare = filelayout_read_prepare,
 448         .rpc_call_done = filelayout_read_call_done,
 449         .rpc_count_stats = filelayout_read_count_stats,
 450         .rpc_release = pnfs_generic_rw_release,
 451 };
 452
 453 static const struct rpc_call_ops filelayout_write_call_ops = {
 454         .rpc_call_prepare = filelayout_write_prepare,
 455         .rpc_call_done = filelayout_write_call_done,
 456         .rpc_count_stats = filelayout_write_count_stats,
 457         .rpc_release = pnfs_generic_rw_release,
 458 };
 459
 460 static const struct rpc_call_ops filelayout_commit_call_ops = {
 461         .rpc_call_prepare = filelayout_commit_prepare,
 462         .rpc_call_done = pnfs_generic_write_commit_done,
 463         .rpc_count_stats = filelayout_commit_count_stats,
 464         .rpc_release = pnfs_generic_commit_release,
 465 };
 466
 467 static enum pnfs_try_status
 468 filelayout_read_pagelist(struct nfs_pgio_header *hdr)
 469 {
 470         struct pnfs_layout_segment *lseg = hdr->lseg;
 471         struct nfs4_pnfs_ds *ds;
 472         struct rpc_clnt *ds_clnt;
 473         loff_t offset = hdr->args.offset;
 474         u32 j, idx;
 475         struct nfs_fh *fh;
 476
 477         dprintk("--> %s ino %lu pgbase %u req %Zu@%llu\n",
 478                 __func__, hdr->inode->i_ino,
 479                 hdr->args.pgbase, (size_t)hdr->args.count, offset);
 480
 481         /* Retrieve the correct rpc_client for the byte range */
 482         j = nfs4_fl_calc_j_index(lseg, offset);
 483         idx = nfs4_fl_calc_ds_index(lseg, j);
 484         ds = nfs4_fl_prepare_ds(lseg, idx);
 485         if (!ds)
 486                 return PNFS_NOT_ATTEMPTED;
 487
 488         ds_clnt = nfs4_find_or_create_ds_client(ds->ds_clp, hdr->inode);
 489         if (IS_ERR(ds_clnt))
 490                 return PNFS_NOT_ATTEMPTED;
 491
 492         dprintk("%s USE DS: %s cl_count %d\n", __func__,
 493                 ds->ds_remotestr, atomic_read(&ds->ds_clp->cl_count));
 494
 495         /* No multipath support. Use first DS */
 496         atomic_inc(&ds->ds_clp->cl_count);
 497         hdr->ds_clp = ds->ds_clp;
 498         hdr->ds_commit_idx = idx;
 499         fh = nfs4_fl_select_ds_fh(lseg, j);
 500         if (fh)
 501                 hdr->args.fh = fh;
 502
 503         hdr->args.offset = filelayout_get_dserver_offset(lseg, offset);
 504         hdr->mds_offset = offset;
 505
 506         /* Perform an asynchronous read to ds */
 507         nfs_initiate_pgio(ds_clnt, hdr, hdr->cred,
 508                           NFS_PROTO(hdr->inode), &filelayout_read_call_ops,
 509                           0, RPC_TASK_SOFTCONN);
 510         return PNFS_ATTEMPTED;
 511 }
 512
 513 /* Perform async writes. */
 514 static enum pnfs_try_status
 515 filelayout_write_pagelist(struct nfs_pgio_header *hdr, int sync)
 516 {
 517         struct pnfs_layout_segment *lseg = hdr->lseg;
 518         struct nfs4_pnfs_ds *ds;
 519         struct rpc_clnt *ds_clnt;
 520         loff_t offset = hdr->args.offset;
 521         u32 j, idx;
 522         struct nfs_fh *fh;
 523
 524         /* Retrieve the correct rpc_client for the byte range */
 525         j = nfs4_fl_calc_j_index(lseg, offset);
 526         idx = nfs4_fl_calc_ds_index(lseg, j);
 527         ds = nfs4_fl_prepare_ds(lseg, idx);
 528         if (!ds)
 529                 return PNFS_NOT_ATTEMPTED;
 530
 531         ds_clnt = nfs4_find_or_create_ds_client(ds->ds_clp, hdr->inode);
 532         if (IS_ERR(ds_clnt))
 533                 return PNFS_NOT_ATTEMPTED;
 534
 535         dprintk("%s ino %lu sync %d req %Zu@%llu DS: %s cl_count %d\n",
 536                 __func__, hdr->inode->i_ino, sync, (size_t) hdr->args.count,
 537                 offset, ds->ds_remotestr, atomic_read(&ds->ds_clp->cl_count));
 538
 539         hdr->pgio_done_cb = filelayout_write_done_cb;
 540         atomic_inc(&ds->ds_clp->cl_count);
 541         hdr->ds_clp = ds->ds_clp;
 542         hdr->ds_commit_idx = idx;
 543         fh = nfs4_fl_select_ds_fh(lseg, j);
 544         if (fh)
 545                 hdr->args.fh = fh;
 546         hdr->args.offset = filelayout_get_dserver_offset(lseg, offset);
 547
 548         /* Perform an asynchronous write */
 549         nfs_initiate_pgio(ds_clnt, hdr, hdr->cred,
 550                           NFS_PROTO(hdr->inode), &filelayout_write_call_ops,
 551                           sync, RPC_TASK_SOFTCONN);
 552         return PNFS_ATTEMPTED;
 553 }
 554
 555 /*
 556  * filelayout_check_layout()
 557  *
 558  * Make sure layout segment parameters are sane WRT the device.
 559  * At this point no generic layer initialization of the lseg has occurred,
 560  * and nothing has been added to the layout_hdr cache.
 561  *
 562  */
 563 static int
 564 filelayout_check_layout(struct pnfs_layout_hdr *lo,
 565                         struct nfs4_filelayout_segment *fl,
 566                         struct nfs4_layoutget_res *lgr,
 567                         struct nfs4_deviceid *id,
 568                         gfp_t gfp_flags)
 569 {
 570         struct nfs4_deviceid_node *d;
 571         struct nfs4_file_layout_dsaddr *dsaddr;
 572         int status = -EINVAL;
 573
 574         dprintk("--> %s\n", __func__);
 575
 576         /* FIXME: remove this check when layout segment support is added */
 577         if (lgr->range.offset != 0 ||
 578             lgr->range.length != NFS4_MAX_UINT64) {
 579                 dprintk("%s Only whole file layouts supported. Use MDS i/o\n",
 580                         __func__);
 581                 goto out;
 582         }
 583
 584         if (fl->pattern_offset > lgr->range.offset) {
 585                 dprintk("%s pattern_offset %lld too large\n",
 586                                 __func__, fl->pattern_offset);
 587                 goto out;
 588         }
 589
 590         if (!fl->stripe_unit) {
 591                 dprintk("%s Invalid stripe unit (%u)\n",
 592                         __func__, fl->stripe_unit);
 593                 goto out;
 594         }
 595
 596         /* find and reference the deviceid */
 597         d = nfs4_find_get_deviceid(NFS_SERVER(lo->plh_inode), id,
 598                         lo->plh_lc_cred, gfp_flags);
 599         if (d == NULL)
 600                 goto out;
 601
 602         dsaddr = container_of(d, struct nfs4_file_layout_dsaddr, id_node);
 603         /* Found deviceid is unavailable */
 604         if (filelayout_test_devid_unavailable(&dsaddr->id_node))
 605                 goto out_put;
 606
 607         fl->dsaddr = dsaddr;
 608
 609         if (fl->first_stripe_index >= dsaddr->stripe_count) {
 610                 dprintk("%s Bad first_stripe_index %u\n",
 611                                 __func__, fl->first_stripe_index);
 612                 goto out_put;
 613         }
 614
 615         if ((fl->stripe_type == STRIPE_SPARSE &&
 616             fl->num_fh > 1 && fl->num_fh != dsaddr->ds_num) ||
 617             (fl->stripe_type == STRIPE_DENSE &&
 618             fl->num_fh != dsaddr->stripe_count)) {
 619                 dprintk("%s num_fh %u not valid for given packing\n",
 620                         __func__, fl->num_fh);
 621                 goto out_put;
 622         }
 623
 624         status = 0;
 625 out:
 626         dprintk("--> %s returns %d\n", __func__, status);
 627         return status;
 628 out_put:
 629         nfs4_fl_put_deviceid(dsaddr);
 630         goto out;
 631 }
 632
 633 static void _filelayout_free_lseg(struct nfs4_filelayout_segment *fl)
 634 {
 635         int i;
 636
 637         if (fl->fh_array) {
 638                 for (i = 0; i < fl->num_fh; i++) {
 639                         if (!fl->fh_array[i])
 640                                 break;
 641                         kfree(fl->fh_array[i]);
 642                 }
 643                 kfree(fl->fh_array);
 644         }
 645         kfree(fl);
 646 }
 647
 648 static int
 649 filelayout_decode_layout(struct pnfs_layout_hdr *flo,
 650                          struct nfs4_filelayout_segment *fl,
 651                          struct nfs4_layoutget_res *lgr,
 652                          struct nfs4_deviceid *id,
 653                          gfp_t gfp_flags)
 654 {
 655         struct xdr_stream stream;
 656         struct xdr_buf buf;
 657         struct page *scratch;
 658         __be32 *p;
 659         uint32_t nfl_util;
 660         int i;
 661
 662         dprintk("%s: set_layout_map Begin\n", __func__);
 663
 664         scratch = alloc_page(gfp_flags);
 665         if (!scratch)
 666                 return -ENOMEM;
 667
 668         xdr_init_decode_pages(&stream, &buf, lgr->layoutp->pages, lgr->layoutp->len);
 669         xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
 670
 671         /* 20 = ufl_util (4), first_stripe_index (4), pattern_offset (8),
 672          * num_fh (4) */
 673         p = xdr_inline_decode(&stream, NFS4_DEVICEID4_SIZE + 20);
 674         if (unlikely(!p))
 675                 goto out_err;
 676
 677         memcpy(id, p, sizeof(*id));
 678         p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);
 679         nfs4_print_deviceid(id);
 680
 681         nfl_util = be32_to_cpup(p++);
 682         if (nfl_util & NFL4_UFLG_COMMIT_THRU_MDS)
 683                 fl->commit_through_mds = 1;
 684         if (nfl_util & NFL4_UFLG_DENSE)
 685                 fl->stripe_type = STRIPE_DENSE;
 686         else
 687                 fl->stripe_type = STRIPE_SPARSE;
 688         fl->stripe_unit = nfl_util & ~NFL4_UFLG_MASK;
 689
 690         fl->first_stripe_index = be32_to_cpup(p++);
 691         p = xdr_decode_hyper(p, &fl->pattern_offset);
 692         fl->num_fh = be32_to_cpup(p++);
 693
 694         dprintk("%s: nfl_util 0x%X num_fh %u fsi %u po %llu\n",
 695                 __func__, nfl_util, fl->num_fh, fl->first_stripe_index,
 696                 fl->pattern_offset);
 697
 698         /* Note that a zero value for num_fh is legal for STRIPE_SPARSE.
 699          * Futher checking is done in filelayout_check_layout */
 700         if (fl->num_fh >
 701             max(NFS4_PNFS_MAX_STRIPE_CNT, NFS4_PNFS_MAX_MULTI_CNT))
 702                 goto out_err;
 703
 704         if (fl->num_fh > 0) {
 705                 fl->fh_array = kcalloc(fl->num_fh, sizeof(fl->fh_array[0]),
 706                                        gfp_flags);
 707                 if (!fl->fh_array)
 708                         goto out_err;
 709         }
 710
 711         for (i = 0; i < fl->num_fh; i++) {
 712                 /* Do we want to use a mempool here? */
 713                 fl->fh_array[i] = kmalloc(sizeof(struct nfs_fh), gfp_flags);
 714                 if (!fl->fh_array[i])
 715                         goto out_err;
 716
 717                 p = xdr_inline_decode(&stream, 4);
 718                 if (unlikely(!p))
 719                         goto out_err;
 720                 fl->fh_array[i]->size = be32_to_cpup(p++);
 721                 if (sizeof(struct nfs_fh) < fl->fh_array[i]->size) {
 722                         printk(KERN_ERR "NFS: Too big fh %d received %d\n",
 723                                i, fl->fh_array[i]->size);
 724                         goto out_err;
 725                 }
 726
 727                 p = xdr_inline_decode(&stream, fl->fh_array[i]->size);
 728                 if (unlikely(!p))
 729                         goto out_err;
 730                 memcpy(fl->fh_array[i]->data, p, fl->fh_array[i]->size);
 731                 dprintk("DEBUG: %s: fh len %d\n", __func__,
 732                         fl->fh_array[i]->size);
 733         }
 734
 735         __free_page(scratch);
 736         return 0;
 737
 738 out_err:
 739         __free_page(scratch);
 740         return -EIO;
 741 }
 742
 743 static void
 744 filelayout_free_lseg(struct pnfs_layout_segment *lseg)
 745 {
 746         struct nfs4_filelayout_segment *fl = FILELAYOUT_LSEG(lseg);
 747
 748         dprintk("--> %s\n", __func__);
 749         nfs4_fl_put_deviceid(fl->dsaddr);
 750         /* This assumes a single RW lseg */
 751         if (lseg->pls_range.iomode == IOMODE_RW) {
 752                 struct nfs4_filelayout *flo;
 753
 754                 flo = FILELAYOUT_FROM_HDR(lseg->pls_layout);
 755                 flo->commit_info.nbuckets = 0;
 756                 kfree(flo->commit_info.buckets);
 757                 flo->commit_info.buckets = NULL;
 758         }
 759         _filelayout_free_lseg(fl);
 760 }
 761
 762 static int
 763 filelayout_alloc_commit_info(struct pnfs_layout_segment *lseg,
 764                              struct nfs_commit_info *cinfo,
 765                              gfp_t gfp_flags)
 766 {
 767         struct nfs4_filelayout_segment *fl = FILELAYOUT_LSEG(lseg);
 768         struct pnfs_commit_bucket *buckets;
 769         int size, i;
 770
 771         if (fl->commit_through_mds)
 772                 return 0;
 773
 774         size = (fl->stripe_type == STRIPE_SPARSE) ?
 775                 fl->dsaddr->ds_num : fl->dsaddr->stripe_count;
 776
 777         if (cinfo->ds->nbuckets >= size) {
 778                 /* This assumes there is only one IOMODE_RW lseg.  What
 779                  * we really want to do is have a layout_hdr level
 780                  * dictionary of <multipath_list4, fh> keys, each
 781                  * associated with a struct list_head, populated by calls
 782                  * to filelayout_write_pagelist().
 783                  * */
 784                 return 0;
 785         }
 786
 787         buckets = kcalloc(size, sizeof(struct pnfs_commit_bucket),
 788                           gfp_flags);
 789         if (!buckets)
 790                 return -ENOMEM;
 791         for (i = 0; i < size; i++) {
 792                 INIT_LIST_HEAD(&buckets[i].written);
 793                 INIT_LIST_HEAD(&buckets[i].committing);
 794                 /* mark direct verifier as unset */
 795                 buckets[i].direct_verf.committed = NFS_INVALID_STABLE_HOW;
 796         }
 797
 798         spin_lock(cinfo->lock);
 799         if (cinfo->ds->nbuckets >= size)
 800                 goto out;
 801         for (i = 0; i < cinfo->ds->nbuckets; i++) {
 802                 list_splice(&cinfo->ds->buckets[i].written,
 803                             &buckets[i].written);
 804                 list_splice(&cinfo->ds->buckets[i].committing,
 805                             &buckets[i].committing);
 806                 buckets[i].direct_verf.committed =
 807                         cinfo->ds->buckets[i].direct_verf.committed;
 808                 buckets[i].wlseg = cinfo->ds->buckets[i].wlseg;
 809                 buckets[i].clseg = cinfo->ds->buckets[i].clseg;
 810         }
 811         swap(cinfo->ds->buckets, buckets);
 812         cinfo->ds->nbuckets = size;
 813 out:
 814         spin_unlock(cinfo->lock);
 815         kfree(buckets);
 816         return 0;
 817 }
 818
 819 static struct pnfs_layout_segment *
 820 filelayout_alloc_lseg(struct pnfs_layout_hdr *layoutid,
 821                       struct nfs4_layoutget_res *lgr,
 822                       gfp_t gfp_flags)
 823 {
 824         struct nfs4_filelayout_segment *fl;
 825         int rc;
 826         struct nfs4_deviceid id;
 827
 828         dprintk("--> %s\n", __func__);
 829         fl = kzalloc(sizeof(*fl), gfp_flags);
 830         if (!fl)
 831                 return NULL;
 832
 833         rc = filelayout_decode_layout(layoutid, fl, lgr, &id, gfp_flags);
 834         if (rc != 0 || filelayout_check_layout(layoutid, fl, lgr, &id, gfp_flags)) {
 835                 _filelayout_free_lseg(fl);
 836                 return NULL;
 837         }
 838         return &fl->generic_hdr;
 839 }
 840
 841 /*
 842  * filelayout_pg_test(). Called by nfs_can_coalesce_requests()
 843  *
 844  * Return 0 if @req cannot be coalesced into @pgio, otherwise return the number
 845  * of bytes (maximum @req->wb_bytes) that can be coalesced.
 846  */
 847 static size_t
 848 filelayout_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
 849                    struct nfs_page *req)
 850 {
 851         unsigned int size;
 852         u64 p_stripe, r_stripe;
 853         u32 stripe_offset;
 854         u64 segment_offset = pgio->pg_lseg->pls_range.offset;
 855         u32 stripe_unit = FILELAYOUT_LSEG(pgio->pg_lseg)->stripe_unit;
 856
 857         /* calls nfs_generic_pg_test */
 858         size = pnfs_generic_pg_test(pgio, prev, req);
 859         if (!size)
 860                 return 0;
 861
 862         /* see if req and prev are in the same stripe */
 863         if (prev) {
 864                 p_stripe = (u64)req_offset(prev) - segment_offset;
 865                 r_stripe = (u64)req_offset(req) - segment_offset;
 866                 do_div(p_stripe, stripe_unit);
 867                 do_div(r_stripe, stripe_unit);
 868
 869                 if (p_stripe != r_stripe)
 870                         return 0;
 871         }
 872
 873         /* calculate remaining bytes in the current stripe */
 874         div_u64_rem((u64)req_offset(req) - segment_offset,
 875                         stripe_unit,
 876                         &stripe_offset);
 877         WARN_ON_ONCE(stripe_offset > stripe_unit);
 878         if (stripe_offset >= stripe_unit)
 879                 return 0;
 880         return min(stripe_unit - (unsigned int)stripe_offset, size);
 881 }
 882
 883 static void
 884 filelayout_pg_init_read(struct nfs_pageio_descriptor *pgio,
 885                         struct nfs_page *req)
 886 {
 887         if (!pgio->pg_lseg) {
 888                 pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
 889                                            req->wb_context,
 890                                            0,
 891                                            NFS4_MAX_UINT64,
 892                                            IOMODE_READ,
 893                                            GFP_KERNEL);
 894                 if (IS_ERR(pgio->pg_lseg)) {
 895                         pgio->pg_error = PTR_ERR(pgio->pg_lseg);
 896                         pgio->pg_lseg = NULL;
 897                         return;
 898                 }
 899         }
 900         /* If no lseg, fall back to read through mds */
 901         if (pgio->pg_lseg == NULL)
 902                 nfs_pageio_reset_read_mds(pgio);
 903 }
 904
 905 static void
 906 filelayout_pg_init_write(struct nfs_pageio_descriptor *pgio,
 907                          struct nfs_page *req)
 908 {
 909         struct nfs_commit_info cinfo;
 910         int status;
 911
 912         if (!pgio->pg_lseg) {
 913                 pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
 914                                            req->wb_context,
 915                                            0,
 916                                            NFS4_MAX_UINT64,
 917                                            IOMODE_RW,
 918                                            GFP_NOFS);
 919                 if (IS_ERR(pgio->pg_lseg)) {
 920                         pgio->pg_error = PTR_ERR(pgio->pg_lseg);
 921                         pgio->pg_lseg = NULL;
 922                         return;
 923                 }
 924         }
 925
 926         /* If no lseg, fall back to write through mds */
 927         if (pgio->pg_lseg == NULL)
 928                 goto out_mds;
 929         nfs_init_cinfo(&cinfo, pgio->pg_inode, pgio->pg_dreq);
 930         status = filelayout_alloc_commit_info(pgio->pg_lseg, &cinfo, GFP_NOFS);
 931         if (status < 0) {
 932                 pnfs_put_lseg(pgio->pg_lseg);
 933                 pgio->pg_lseg = NULL;
 934                 goto out_mds;
 935         }
 936         return;
 937 out_mds:
 938         nfs_pageio_reset_write_mds(pgio);
 939 }
 940
 941 static const struct nfs_pageio_ops filelayout_pg_read_ops = {
 942         .pg_init = filelayout_pg_init_read,
 943         .pg_test = filelayout_pg_test,
 944         .pg_doio = pnfs_generic_pg_readpages,
 945         .pg_cleanup = pnfs_generic_pg_cleanup,
 946 };
 947
 948 static const struct nfs_pageio_ops filelayout_pg_write_ops = {
 949         .pg_init = filelayout_pg_init_write,
 950         .pg_test = filelayout_pg_test,
 951         .pg_doio = pnfs_generic_pg_writepages,
 952         .pg_cleanup = pnfs_generic_pg_cleanup,
 953 };
 954
 955 static u32 select_bucket_index(struct nfs4_filelayout_segment *fl, u32 j)
 956 {
 957         if (fl->stripe_type == STRIPE_SPARSE)
 958                 return nfs4_fl_calc_ds_index(&fl->generic_hdr, j);
 959         else
 960                 return j;
 961 }
 962
 963 static void
 964 filelayout_mark_request_commit(struct nfs_page *req,
 965                                struct pnfs_layout_segment *lseg,
 966                                struct nfs_commit_info *cinfo,
 967                                u32 ds_commit_idx)
 968
 969 {
 970         struct nfs4_filelayout_segment *fl = FILELAYOUT_LSEG(lseg);
 971         u32 i, j;
 972
 973         if (fl->commit_through_mds) {
 974                 nfs_request_add_commit_list(req, &cinfo->mds->list, cinfo);
 975         } else {
 976                 /* Note that we are calling nfs4_fl_calc_j_index on each page
 977                  * that ends up being committed to a data server.  An attractive
 978                  * alternative is to add a field to nfs_write_data and nfs_page
 979                  * to store the value calculated in filelayout_write_pagelist
 980                  * and just use that here.
 981                  */
 982                 j = nfs4_fl_calc_j_index(lseg, req_offset(req));
 983                 i = select_bucket_index(fl, j);
 984                 pnfs_layout_mark_request_commit(req, lseg, cinfo, i);
 985         }
 986 }
 987
 988 static u32 calc_ds_index_from_commit(struct pnfs_layout_segment *lseg, u32 i)
 989 {
 990         struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
 991
 992         if (flseg->stripe_type == STRIPE_SPARSE)
 993                 return i;
 994         else
 995                 return nfs4_fl_calc_ds_index(lseg, i);
 996 }
 997
 998 static struct nfs_fh *
 999 select_ds_fh_from_commit(struct pnfs_layout_segment *lseg, u32 i)
1000 {
1001         struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
1002
1003         if (flseg->stripe_type == STRIPE_SPARSE) {
1004                 if (flseg->num_fh == 1)
1005                         i = 0;
1006                 else if (flseg->num_fh == 0)
1007                         /* Use the MDS OPEN fh set in nfs_read_rpcsetup */
1008                         return NULL;
1009         }
1010         return flseg->fh_array[i];
1011 }
1012
1013 static int filelayout_initiate_commit(struct nfs_commit_data *data, int how)
1014 {
1015         struct pnfs_layout_segment *lseg = data->lseg;
1016         struct nfs4_pnfs_ds *ds;
1017         struct rpc_clnt *ds_clnt;
1018         u32 idx;
1019         struct nfs_fh *fh;
1020
1021         idx = calc_ds_index_from_commit(lseg, data->ds_commit_index);
1022         ds = nfs4_fl_prepare_ds(lseg, idx);
1023         if (!ds)
1024                 goto out_err;
1025
1026         ds_clnt = nfs4_find_or_create_ds_client(ds->ds_clp, data->inode);
1027         if (IS_ERR(ds_clnt))
1028                 goto out_err;
1029
1030         dprintk("%s ino %lu, how %d cl_count %d\n", __func__,
1031                 data->inode->i_ino, how, atomic_read(&ds->ds_clp->cl_count));
1032         data->commit_done_cb = filelayout_commit_done_cb;
1033         atomic_inc(&ds->ds_clp->cl_count);
1034         data->ds_clp = ds->ds_clp;
1035         fh = select_ds_fh_from_commit(lseg, data->ds_commit_index);
1036         if (fh)
1037                 data->args.fh = fh;
1038         return nfs_initiate_commit(ds_clnt, data, NFS_PROTO(data->inode),
1039                                    &filelayout_commit_call_ops, how,
1040                                    RPC_TASK_SOFTCONN);
1041 out_err:
1042         pnfs_generic_prepare_to_resend_writes(data);
1043         pnfs_generic_commit_release(data);
1044         return -EAGAIN;
1045 }
1046
1047 /* filelayout_search_commit_reqs - Search lists in @cinfo for the head reqest
1048  *                                 for @page
1049  * @cinfo - commit info for current inode
1050  * @page - page to search for matching head request
1051  *
1052  * Returns a the head request if one is found, otherwise returns NULL.
1053  */
1054 static struct nfs_page *
1055 filelayout_search_commit_reqs(struct nfs_commit_info *cinfo, struct page *page)
1056 {
1057         struct nfs_page *freq, *t;
1058         struct pnfs_commit_bucket *b;
1059         int i;
1060
1061         /* Linearly search the commit lists for each bucket until a matching
1062          * request is found */
1063         for (i = 0, b = cinfo->ds->buckets; i < cinfo->ds->nbuckets; i++, b++) {
1064                 list_for_each_entry_safe(freq, t, &b->written, wb_list) {
1065                         if (freq->wb_page == page)
1066                                 return freq->wb_head;
1067                 }
1068                 list_for_each_entry_safe(freq, t, &b->committing, wb_list) {
1069                         if (freq->wb_page == page)
1070                                 return freq->wb_head;
1071                 }
1072         }
1073
1074         return NULL;
1075 }
1076
1077 static int
1078 filelayout_commit_pagelist(struct inode *inode, struct list_head *mds_pages,
1079                            int how, struct nfs_commit_info *cinfo)
1080 {
1081         return pnfs_generic_commit_pagelist(inode, mds_pages, how, cinfo,
1082                                             filelayout_initiate_commit);
1083 }
1084
1085 static struct nfs4_deviceid_node *
1086 filelayout_alloc_deviceid_node(struct nfs_server *server,
1087                 struct pnfs_device *pdev, gfp_t gfp_flags)
1088 {
1089         struct nfs4_file_layout_dsaddr *dsaddr;
1090
1091         dsaddr = nfs4_fl_alloc_deviceid_node(server, pdev, gfp_flags);
1092         if (!dsaddr)
1093                 return NULL;
1094         return &dsaddr->id_node;
1095 }
1096
1097 static void
1098 filelayout_free_deviceid_node(struct nfs4_deviceid_node *d)
1099 {
1100         nfs4_fl_free_deviceid(container_of(d, struct nfs4_file_layout_dsaddr, id_node));
1101 }
1102
1103 static struct pnfs_layout_hdr *
1104 filelayout_alloc_layout_hdr(struct inode *inode, gfp_t gfp_flags)
1105 {
1106         struct nfs4_filelayout *flo;
1107
1108         flo = kzalloc(sizeof(*flo), gfp_flags);
1109         return flo != NULL ? &flo->generic_hdr : NULL;
1110 }
1111
1112 static void
1113 filelayout_free_layout_hdr(struct pnfs_layout_hdr *lo)
1114 {
1115         kfree(FILELAYOUT_FROM_HDR(lo));
1116 }
1117
1118 static struct pnfs_ds_commit_info *
1119 filelayout_get_ds_info(struct inode *inode)
1120 {
1121         struct pnfs_layout_hdr *layout = NFS_I(inode)->layout;
1122
1123         if (layout == NULL)
1124                 return NULL;
1125         else
1126                 return &FILELAYOUT_FROM_HDR(layout)->commit_info;
1127 }
1128
1129 static struct pnfs_layoutdriver_type filelayout_type = {
1130         .id                     = LAYOUT_NFSV4_1_FILES,
1131         .name                   = "LAYOUT_NFSV4_1_FILES",
1132         .owner                  = THIS_MODULE,
1133         .alloc_layout_hdr       = filelayout_alloc_layout_hdr,
1134         .free_layout_hdr        = filelayout_free_layout_hdr,
1135         .alloc_lseg             = filelayout_alloc_lseg,
1136         .free_lseg              = filelayout_free_lseg,
1137         .pg_read_ops            = &filelayout_pg_read_ops,
1138         .pg_write_ops           = &filelayout_pg_write_ops,
1139         .get_ds_info            = &filelayout_get_ds_info,
1140         .mark_request_commit    = filelayout_mark_request_commit,
1141         .clear_request_commit   = pnfs_generic_clear_request_commit,
1142         .scan_commit_lists      = pnfs_generic_scan_commit_lists,
1143         .recover_commit_reqs    = pnfs_generic_recover_commit_reqs,
1144         .search_commit_reqs     = filelayout_search_commit_reqs,
1145         .commit_pagelist        = filelayout_commit_pagelist,
1146         .read_pagelist          = filelayout_read_pagelist,
1147         .write_pagelist         = filelayout_write_pagelist,
1148         .alloc_deviceid_node    = filelayout_alloc_deviceid_node,
1149         .free_deviceid_node     = filelayout_free_deviceid_node,
1150         .sync                   = pnfs_nfs_generic_sync,
1151 };
1152
1153 static int __init nfs4filelayout_init(void)
1154 {
1155         printk(KERN_INFO "%s: NFSv4 File Layout Driver Registering...\n",
1156                __func__);
1157         return pnfs_register_layoutdriver(&filelayout_type);
1158 }
1159
1160 static void __exit nfs4filelayout_exit(void)
1161 {
1162         printk(KERN_INFO "%s: NFSv4 File Layout Driver Unregistering...\n",
1163                __func__);
1164         pnfs_unregister_layoutdriver(&filelayout_type);
1165 }
1166
1167 MODULE_ALIAS("nfs-layouttype4-1");
1168
1169 module_init(nfs4filelayout_init);
1170 module_exit(nfs4filelayout_exit);