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
  36 #include <linux/sunrpc/metrics.h>
  37
  38 #include "../nfs4session.h"
  39 #include "../internal.h"
  40 #include "../delegation.h"
  41 #include "filelayout.h"
  42 #include "../nfs4trace.h"
  43
  44 #define NFSDBG_FACILITY         NFSDBG_PNFS_LD
  45
  46 MODULE_LICENSE("GPL");
  47 MODULE_AUTHOR("Dean Hildebrand <dhildebz@umich.edu>");
  48 MODULE_DESCRIPTION("The NFSv4 file layout driver");
  49
  50 #define FILELAYOUT_POLL_RETRY_MAX     (15*HZ)
  51
  52 static loff_t
  53 filelayout_get_dense_offset(struct nfs4_filelayout_segment *flseg,
  54                             loff_t offset)
  55 {
  56         u32 stripe_width = flseg->stripe_unit * flseg->dsaddr->stripe_count;
  57         u64 stripe_no;
  58         u32 rem;
  59
  60         offset -= flseg->pattern_offset;
  61         stripe_no = div_u64(offset, stripe_width);
  62         div_u64_rem(offset, flseg->stripe_unit, &rem);
  63
  64         return stripe_no * flseg->stripe_unit + rem;
  65 }
  66
  67 /* This function is used by the layout driver to calculate the
  68  * offset of the file on the dserver based on whether the
  69  * layout type is STRIPE_DENSE or STRIPE_SPARSE
  70  */
  71 static loff_t
  72 filelayout_get_dserver_offset(struct pnfs_layout_segment *lseg, loff_t offset)
  73 {
  74         struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
  75
  76         switch (flseg->stripe_type) {
  77         case STRIPE_SPARSE:
  78                 return offset;
  79
  80         case STRIPE_DENSE:
  81                 return filelayout_get_dense_offset(flseg, offset);
  82         }
  83
  84         BUG();
  85 }
  86
  87 static void filelayout_reset_write(struct nfs_pgio_header *hdr)
  88 {
  89         struct rpc_task *task = &hdr->task;
  90
  91         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
  92                 dprintk("%s Reset task %5u for i/o through MDS "
  93                         "(req %s/%llu, %u bytes @ offset %llu)\n", __func__,
  94                         hdr->task.tk_pid,
  95                         hdr->inode->i_sb->s_id,
  96                         (unsigned long long)NFS_FILEID(hdr->inode),
  97                         hdr->args.count,
  98                         (unsigned long long)hdr->args.offset);
  99
 100                 task->tk_status = pnfs_write_done_resend_to_mds(hdr);
 101         }
 102 }
 103
 104 static void filelayout_reset_read(struct nfs_pgio_header *hdr)
 105 {
 106         struct rpc_task *task = &hdr->task;
 107
 108         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
 109                 dprintk("%s Reset task %5u for i/o through MDS "
 110                         "(req %s/%llu, %u bytes @ offset %llu)\n", __func__,
 111                         hdr->task.tk_pid,
 112                         hdr->inode->i_sb->s_id,
 113                         (unsigned long long)NFS_FILEID(hdr->inode),
 114                         hdr->args.count,
 115                         (unsigned long long)hdr->args.offset);
 116
 117                 task->tk_status = pnfs_read_done_resend_to_mds(hdr);
 118         }
 119 }
 120
 121 static int filelayout_async_handle_error(struct rpc_task *task,
 122                                          struct nfs4_state *state,
 123                                          struct nfs_client *clp,
 124                                          struct pnfs_layout_segment *lseg)
 125 {
 126         struct pnfs_layout_hdr *lo = lseg->pls_layout;
 127         struct inode *inode = lo->plh_inode;
 128         struct nfs_server *mds_server = NFS_SERVER(inode);
 129         struct nfs4_deviceid_node *devid = FILELAYOUT_DEVID_NODE(lseg);
 130         struct nfs_client *mds_client = mds_server->nfs_client;
 131         struct nfs4_slot_table *tbl = &clp->cl_session->fc_slot_table;
 132
 133         if (task->tk_status >= 0)
 134                 return 0;
 135
 136         switch (task->tk_status) {
 137         /* MDS state errors */
 138         case -NFS4ERR_DELEG_REVOKED:
 139         case -NFS4ERR_ADMIN_REVOKED:
 140         case -NFS4ERR_BAD_STATEID:
 141         case -NFS4ERR_OPENMODE:
 142                 if (state == NULL)
 143                         break;
 144                 if (nfs4_schedule_stateid_recovery(mds_server, state) < 0)
 145                         goto out_bad_stateid;
 146                 goto wait_on_recovery;
 147         case -NFS4ERR_EXPIRED:
 148                 if (state != NULL) {
 149                         if (nfs4_schedule_stateid_recovery(mds_server, state) < 0)
 150                                 goto out_bad_stateid;
 151                 }
 152                 nfs4_schedule_lease_recovery(mds_client);
 153                 goto wait_on_recovery;
 154         /* DS session errors */
 155         case -NFS4ERR_BADSESSION:
 156         case -NFS4ERR_BADSLOT:
 157         case -NFS4ERR_BAD_HIGH_SLOT:
 158         case -NFS4ERR_DEADSESSION:
 159         case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
 160         case -NFS4ERR_SEQ_FALSE_RETRY:
 161         case -NFS4ERR_SEQ_MISORDERED:
 162                 dprintk("%s ERROR %d, Reset session. Exchangeid "
 163                         "flags 0x%x\n", __func__, task->tk_status,
 164                         clp->cl_exchange_flags);
 165                 nfs4_schedule_session_recovery(clp->cl_session, task->tk_status);
 166                 break;
 167         case -NFS4ERR_DELAY:
 168         case -NFS4ERR_GRACE:
 169                 rpc_delay(task, FILELAYOUT_POLL_RETRY_MAX);
 170                 break;
 171         case -NFS4ERR_RETRY_UNCACHED_REP:
 172                 break;
 173         /* Invalidate Layout errors */
 174         case -NFS4ERR_PNFS_NO_LAYOUT:
 175         case -ESTALE:           /* mapped NFS4ERR_STALE */
 176         case -EBADHANDLE:       /* mapped NFS4ERR_BADHANDLE */
 177         case -EISDIR:           /* mapped NFS4ERR_ISDIR */
 178         case -NFS4ERR_FHEXPIRED:
 179         case -NFS4ERR_WRONG_TYPE:
 180                 dprintk("%s Invalid layout error %d\n", __func__,
 181                         task->tk_status);
 182                 /*
 183                  * Destroy layout so new i/o will get a new layout.
 184                  * Layout will not be destroyed until all current lseg
 185                  * references are put. Mark layout as invalid to resend failed
 186                  * i/o and all i/o waiting on the slot table to the MDS until
 187                  * layout is destroyed and a new valid layout is obtained.
 188                  */
 189                 pnfs_destroy_layout(NFS_I(inode));
 190                 rpc_wake_up(&tbl->slot_tbl_waitq);
 191                 goto reset;
 192         /* RPC connection errors */
 193         case -ECONNREFUSED:
 194         case -EHOSTDOWN:
 195         case -EHOSTUNREACH:
 196         case -ENETUNREACH:
 197         case -EIO:
 198         case -ETIMEDOUT:
 199         case -EPIPE:
 200                 dprintk("%s DS connection error %d\n", __func__,
 201                         task->tk_status);
 202                 nfs4_mark_deviceid_unavailable(devid);
 203                 set_bit(NFS_LAYOUT_RETURN, &lo->plh_flags);
 204                 rpc_wake_up(&tbl->slot_tbl_waitq);
 205                 /* fall through */
 206         default:
 207 reset:
 208                 dprintk("%s Retry through MDS. Error %d\n", __func__,
 209                         task->tk_status);
 210                 return -NFS4ERR_RESET_TO_MDS;
 211         }
 212 out:
 213         task->tk_status = 0;
 214         return -EAGAIN;
 215 out_bad_stateid:
 216         task->tk_status = -EIO;
 217         return 0;
 218 wait_on_recovery:
 219         rpc_sleep_on(&mds_client->cl_rpcwaitq, task, NULL);
 220         if (test_bit(NFS4CLNT_MANAGER_RUNNING, &mds_client->cl_state) == 0)
 221                 rpc_wake_up_queued_task(&mds_client->cl_rpcwaitq, task);
 222         goto out;
 223 }
 224
 225 /* NFS_PROTO call done callback routines */
 226
 227 static int filelayout_read_done_cb(struct rpc_task *task,
 228                                 struct nfs_pgio_header *hdr)
 229 {
 230         int err;
 231
 232         trace_nfs4_pnfs_read(hdr, task->tk_status);
 233         err = filelayout_async_handle_error(task, hdr->args.context->state,
 234                                             hdr->ds_clp, hdr->lseg);
 235
 236         switch (err) {
 237         case -NFS4ERR_RESET_TO_MDS:
 238                 filelayout_reset_read(hdr);
 239                 return task->tk_status;
 240         case -EAGAIN:
 241                 rpc_restart_call_prepare(task);
 242                 return -EAGAIN;
 243         }
 244
 245         return 0;
 246 }
 247
 248 /*
 249  * We reference the rpc_cred of the first WRITE that triggers the need for
 250  * a LAYOUTCOMMIT, and use it to send the layoutcommit compound.
 251  * rfc5661 is not clear about which credential should be used.
 252  */
 253 static void
 254 filelayout_set_layoutcommit(struct nfs_pgio_header *hdr)
 255 {
 256
 257         if (FILELAYOUT_LSEG(hdr->lseg)->commit_through_mds ||
 258             hdr->res.verf->committed != NFS_DATA_SYNC)
 259                 return;
 260
 261         pnfs_set_layoutcommit(hdr);
 262         dprintk("%s inode %lu pls_end_pos %lu\n", __func__, hdr->inode->i_ino,
 263                 (unsigned long) NFS_I(hdr->inode)->layout->plh_lwb);
 264 }
 265
 266 bool
 267 filelayout_test_devid_unavailable(struct nfs4_deviceid_node *node)
 268 {
 269         return filelayout_test_devid_invalid(node) ||
 270                 nfs4_test_deviceid_unavailable(node);
 271 }
 272
 273 static bool
 274 filelayout_reset_to_mds(struct pnfs_layout_segment *lseg)
 275 {
 276         struct nfs4_deviceid_node *node = FILELAYOUT_DEVID_NODE(lseg);
 277
 278         return filelayout_test_devid_unavailable(node);
 279 }
 280
 281 /*
 282  * Call ops for the async read/write cases
 283  * In the case of dense layouts, the offset needs to be reset to its
 284  * original value.
 285  */
 286 static void filelayout_read_prepare(struct rpc_task *task, void *data)
 287 {
 288         struct nfs_pgio_header *hdr = data;
 289
 290         if (unlikely(test_bit(NFS_CONTEXT_BAD, &hdr->args.context->flags))) {
 291                 rpc_exit(task, -EIO);
 292                 return;
 293         }
 294         if (filelayout_reset_to_mds(hdr->lseg)) {
 295                 dprintk("%s task %u reset io to MDS\n", __func__, task->tk_pid);
 296                 filelayout_reset_read(hdr);
 297                 rpc_exit(task, 0);
 298                 return;
 299         }
 300         hdr->pgio_done_cb = filelayout_read_done_cb;
 301
 302         if (nfs41_setup_sequence(hdr->ds_clp->cl_session,
 303                         &hdr->args.seq_args,
 304                         &hdr->res.seq_res,
 305                         task))
 306                 return;
 307         if (nfs4_set_rw_stateid(&hdr->args.stateid, hdr->args.context,
 308                         hdr->args.lock_context, FMODE_READ) == -EIO)
 309                 rpc_exit(task, -EIO); /* lost lock, terminate I/O */
 310 }
 311
 312 static void filelayout_read_call_done(struct rpc_task *task, void *data)
 313 {
 314         struct nfs_pgio_header *hdr = data;
 315
 316         dprintk("--> %s task->tk_status %d\n", __func__, task->tk_status);
 317
 318         if (test_bit(NFS_IOHDR_REDO, &hdr->flags) &&
 319             task->tk_status == 0) {
 320                 nfs41_sequence_done(task, &hdr->res.seq_res);
 321                 return;
 322         }
 323
 324         /* Note this may cause RPC to be resent */
 325         hdr->mds_ops->rpc_call_done(task, data);
 326 }
 327
 328 static void filelayout_read_count_stats(struct rpc_task *task, void *data)
 329 {
 330         struct nfs_pgio_header *hdr = data;
 331
 332         rpc_count_iostats(task, NFS_SERVER(hdr->inode)->client->cl_metrics);
 333 }
 334
 335 static int filelayout_write_done_cb(struct rpc_task *task,
 336                                 struct nfs_pgio_header *hdr)
 337 {
 338         int err;
 339
 340         trace_nfs4_pnfs_write(hdr, task->tk_status);
 341         err = filelayout_async_handle_error(task, hdr->args.context->state,
 342                                             hdr->ds_clp, hdr->lseg);
 343
 344         switch (err) {
 345         case -NFS4ERR_RESET_TO_MDS:
 346                 filelayout_reset_write(hdr);
 347                 return task->tk_status;
 348         case -EAGAIN:
 349                 rpc_restart_call_prepare(task);
 350                 return -EAGAIN;
 351         }
 352
 353         filelayout_set_layoutcommit(hdr);
 354         return 0;
 355 }
 356
 357 static int filelayout_commit_done_cb(struct rpc_task *task,
 358                                      struct nfs_commit_data *data)
 359 {
 360         int err;
 361
 362         trace_nfs4_pnfs_commit_ds(data, task->tk_status);
 363         err = filelayout_async_handle_error(task, NULL, data->ds_clp,
 364                                             data->lseg);
 365
 366         switch (err) {
 367         case -NFS4ERR_RESET_TO_MDS:
 368                 pnfs_generic_prepare_to_resend_writes(data);
 369                 return -EAGAIN;
 370         case -EAGAIN:
 371                 rpc_restart_call_prepare(task);
 372                 return -EAGAIN;
 373         }
 374
 375         if (data->verf.committed == NFS_UNSTABLE)
 376                 pnfs_commit_set_layoutcommit(data);
 377
 378         return 0;
 379 }
 380
 381 static void filelayout_write_prepare(struct rpc_task *task, void *data)
 382 {
 383         struct nfs_pgio_header *hdr = data;
 384
 385         if (unlikely(test_bit(NFS_CONTEXT_BAD, &hdr->args.context->flags))) {
 386                 rpc_exit(task, -EIO);
 387                 return;
 388         }
 389         if (filelayout_reset_to_mds(hdr->lseg)) {
 390                 dprintk("%s task %u reset io to MDS\n", __func__, task->tk_pid);
 391                 filelayout_reset_write(hdr);
 392                 rpc_exit(task, 0);
 393                 return;
 394         }
 395         if (nfs41_setup_sequence(hdr->ds_clp->cl_session,
 396                         &hdr->args.seq_args,
 397                         &hdr->res.seq_res,
 398                         task))
 399                 return;
 400         if (nfs4_set_rw_stateid(&hdr->args.stateid, hdr->args.context,
 401                         hdr->args.lock_context, FMODE_WRITE) == -EIO)
 402                 rpc_exit(task, -EIO); /* lost lock, terminate I/O */
 403 }
 404
 405 static void filelayout_write_call_done(struct rpc_task *task, void *data)
 406 {
 407         struct nfs_pgio_header *hdr = data;
 408
 409         if (test_bit(NFS_IOHDR_REDO, &hdr->flags) &&
 410             task->tk_status == 0) {
 411                 nfs41_sequence_done(task, &hdr->res.seq_res);
 412                 return;
 413         }
 414
 415         /* Note this may cause RPC to be resent */
 416         hdr->mds_ops->rpc_call_done(task, data);
 417 }
 418
 419 static void filelayout_write_count_stats(struct rpc_task *task, void *data)
 420 {
 421         struct nfs_pgio_header *hdr = data;
 422
 423         rpc_count_iostats(task, NFS_SERVER(hdr->inode)->client->cl_metrics);
 424 }
 425
 426 static void filelayout_commit_prepare(struct rpc_task *task, void *data)
 427 {
 428         struct nfs_commit_data *wdata = data;
 429
 430         nfs41_setup_sequence(wdata->ds_clp->cl_session,
 431                         &wdata->args.seq_args,
 432                         &wdata->res.seq_res,
 433                         task);
 434 }
 435
 436 static void filelayout_commit_count_stats(struct rpc_task *task, void *data)
 437 {
 438         struct nfs_commit_data *cdata = data;
 439
 440         rpc_count_iostats(task, NFS_SERVER(cdata->inode)->client->cl_metrics);
 441 }
 442
 443 static const struct rpc_call_ops filelayout_read_call_ops = {
 444         .rpc_call_prepare = filelayout_read_prepare,
 445         .rpc_call_done = filelayout_read_call_done,
 446         .rpc_count_stats = filelayout_read_count_stats,
 447         .rpc_release = pnfs_generic_rw_release,
 448 };
 449
 450 static const struct rpc_call_ops filelayout_write_call_ops = {
 451         .rpc_call_prepare = filelayout_write_prepare,
 452         .rpc_call_done = filelayout_write_call_done,
 453         .rpc_count_stats = filelayout_write_count_stats,
 454         .rpc_release = pnfs_generic_rw_release,
 455 };
 456
 457 static const struct rpc_call_ops filelayout_commit_call_ops = {
 458         .rpc_call_prepare = filelayout_commit_prepare,
 459         .rpc_call_done = pnfs_generic_write_commit_done,
 460         .rpc_count_stats = filelayout_commit_count_stats,
 461         .rpc_release = pnfs_generic_commit_release,
 462 };
 463
 464 static enum pnfs_try_status
 465 filelayout_read_pagelist(struct nfs_pgio_header *hdr)
 466 {
 467         struct pnfs_layout_segment *lseg = hdr->lseg;
 468         struct nfs4_pnfs_ds *ds;
 469         struct rpc_clnt *ds_clnt;
 470         loff_t offset = hdr->args.offset;
 471         u32 j, idx;
 472         struct nfs_fh *fh;
 473
 474         dprintk("--> %s ino %lu pgbase %u req %Zu@%llu\n",
 475                 __func__, hdr->inode->i_ino,
 476                 hdr->args.pgbase, (size_t)hdr->args.count, offset);
 477
 478         /* Retrieve the correct rpc_client for the byte range */
 479         j = nfs4_fl_calc_j_index(lseg, offset);
 480         idx = nfs4_fl_calc_ds_index(lseg, j);
 481         ds = nfs4_fl_prepare_ds(lseg, idx);
 482         if (!ds)
 483                 return PNFS_NOT_ATTEMPTED;
 484
 485         ds_clnt = nfs4_find_or_create_ds_client(ds->ds_clp, hdr->inode);
 486         if (IS_ERR(ds_clnt))
 487                 return PNFS_NOT_ATTEMPTED;
 488
 489         dprintk("%s USE DS: %s cl_count %d\n", __func__,
 490                 ds->ds_remotestr, atomic_read(&ds->ds_clp->cl_count));
 491
 492         /* No multipath support. Use first DS */
 493         atomic_inc(&ds->ds_clp->cl_count);
 494         hdr->ds_clp = ds->ds_clp;
 495         hdr->ds_idx = idx;
 496         fh = nfs4_fl_select_ds_fh(lseg, j);
 497         if (fh)
 498                 hdr->args.fh = fh;
 499
 500         hdr->args.offset = filelayout_get_dserver_offset(lseg, offset);
 501         hdr->mds_offset = offset;
 502
 503         /* Perform an asynchronous read to ds */
 504         nfs_initiate_pgio(ds_clnt, hdr,
 505                             &filelayout_read_call_ops, 0, RPC_TASK_SOFTCONN);
 506         return PNFS_ATTEMPTED;
 507 }
 508
 509 /* Perform async writes. */
 510 static enum pnfs_try_status
 511 filelayout_write_pagelist(struct nfs_pgio_header *hdr, int sync)
 512 {
 513         struct pnfs_layout_segment *lseg = hdr->lseg;
 514         struct nfs4_pnfs_ds *ds;
 515         struct rpc_clnt *ds_clnt;
 516         loff_t offset = hdr->args.offset;
 517         u32 j, idx;
 518         struct nfs_fh *fh;
 519
 520         /* Retrieve the correct rpc_client for the byte range */
 521         j = nfs4_fl_calc_j_index(lseg, offset);
 522         idx = nfs4_fl_calc_ds_index(lseg, j);
 523         ds = nfs4_fl_prepare_ds(lseg, idx);
 524         if (!ds)
 525                 return PNFS_NOT_ATTEMPTED;
 526
 527         ds_clnt = nfs4_find_or_create_ds_client(ds->ds_clp, hdr->inode);
 528         if (IS_ERR(ds_clnt))
 529                 return PNFS_NOT_ATTEMPTED;
 530
 531         dprintk("%s ino %lu sync %d req %Zu@%llu DS: %s cl_count %d\n",
 532                 __func__, hdr->inode->i_ino, sync, (size_t) hdr->args.count,
 533                 offset, ds->ds_remotestr, atomic_read(&ds->ds_clp->cl_count));
 534
 535         hdr->pgio_done_cb = filelayout_write_done_cb;
 536         atomic_inc(&ds->ds_clp->cl_count);
 537         hdr->ds_clp = ds->ds_clp;
 538         hdr->ds_idx = idx;
 539         fh = nfs4_fl_select_ds_fh(lseg, j);
 540         if (fh)
 541                 hdr->args.fh = fh;
 542         hdr->args.offset = filelayout_get_dserver_offset(lseg, offset);
 543
 544         /* Perform an asynchronous write */
 545         nfs_initiate_pgio(ds_clnt, hdr,
 546                                     &filelayout_write_call_ops, sync,
 547                                     RPC_TASK_SOFTCONN);
 548         return PNFS_ATTEMPTED;
 549 }
 550
 551 /*
 552  * filelayout_check_layout()
 553  *
 554  * Make sure layout segment parameters are sane WRT the device.
 555  * At this point no generic layer initialization of the lseg has occurred,
 556  * and nothing has been added to the layout_hdr cache.
 557  *
 558  */
 559 static int
 560 filelayout_check_layout(struct pnfs_layout_hdr *lo,
 561                         struct nfs4_filelayout_segment *fl,
 562                         struct nfs4_layoutget_res *lgr,
 563                         struct nfs4_deviceid *id,
 564                         gfp_t gfp_flags)
 565 {
 566         struct nfs4_deviceid_node *d;
 567         struct nfs4_file_layout_dsaddr *dsaddr;
 568         int status = -EINVAL;
 569
 570         dprintk("--> %s\n", __func__);
 571
 572         /* FIXME: remove this check when layout segment support is added */
 573         if (lgr->range.offset != 0 ||
 574             lgr->range.length != NFS4_MAX_UINT64) {
 575                 dprintk("%s Only whole file layouts supported. Use MDS i/o\n",
 576                         __func__);
 577                 goto out;
 578         }
 579
 580         if (fl->pattern_offset > lgr->range.offset) {
 581                 dprintk("%s pattern_offset %lld too large\n",
 582                                 __func__, fl->pattern_offset);
 583                 goto out;
 584         }
 585
 586         if (!fl->stripe_unit) {
 587                 dprintk("%s Invalid stripe unit (%u)\n",
 588                         __func__, fl->stripe_unit);
 589                 goto out;
 590         }
 591
 592         /* find and reference the deviceid */
 593         d = nfs4_find_get_deviceid(NFS_SERVER(lo->plh_inode), id,
 594                         lo->plh_lc_cred, gfp_flags);
 595         if (d == NULL)
 596                 goto out;
 597
 598         dsaddr = container_of(d, struct nfs4_file_layout_dsaddr, id_node);
 599         /* Found deviceid is unavailable */
 600         if (filelayout_test_devid_unavailable(&dsaddr->id_node))
 601                 goto out_put;
 602
 603         fl->dsaddr = dsaddr;
 604
 605         if (fl->first_stripe_index >= dsaddr->stripe_count) {
 606                 dprintk("%s Bad first_stripe_index %u\n",
 607                                 __func__, fl->first_stripe_index);
 608                 goto out_put;
 609         }
 610
 611         if ((fl->stripe_type == STRIPE_SPARSE &&
 612             fl->num_fh > 1 && fl->num_fh != dsaddr->ds_num) ||
 613             (fl->stripe_type == STRIPE_DENSE &&
 614             fl->num_fh != dsaddr->stripe_count)) {
 615                 dprintk("%s num_fh %u not valid for given packing\n",
 616                         __func__, fl->num_fh);
 617                 goto out_put;
 618         }
 619
 620         status = 0;
 621 out:
 622         dprintk("--> %s returns %d\n", __func__, status);
 623         return status;
 624 out_put:
 625         nfs4_fl_put_deviceid(dsaddr);
 626         goto out;
 627 }
 628
 629 static void filelayout_free_fh_array(struct nfs4_filelayout_segment *fl)
 630 {
 631         int i;
 632
 633         for (i = 0; i < fl->num_fh; i++) {
 634                 if (!fl->fh_array[i])
 635                         break;
 636                 kfree(fl->fh_array[i]);
 637         }
 638         kfree(fl->fh_array);
 639         fl->fh_array = NULL;
 640 }
 641
 642 static void
 643 _filelayout_free_lseg(struct nfs4_filelayout_segment *fl)
 644 {
 645         filelayout_free_fh_array(fl);
 646         kfree(fl);
 647 }
 648
 649 static int
 650 filelayout_decode_layout(struct pnfs_layout_hdr *flo,
 651                          struct nfs4_filelayout_segment *fl,
 652                          struct nfs4_layoutget_res *lgr,
 653                          struct nfs4_deviceid *id,
 654                          gfp_t gfp_flags)
 655 {
 656         struct xdr_stream stream;
 657         struct xdr_buf buf;
 658         struct page *scratch;
 659         __be32 *p;
 660         uint32_t nfl_util;
 661         int i;
 662
 663         dprintk("%s: set_layout_map Begin\n", __func__);
 664
 665         scratch = alloc_page(gfp_flags);
 666         if (!scratch)
 667                 return -ENOMEM;
 668
 669         xdr_init_decode_pages(&stream, &buf, lgr->layoutp->pages, lgr->layoutp->len);
 670         xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
 671
 672         /* 20 = ufl_util (4), first_stripe_index (4), pattern_offset (8),
 673          * num_fh (4) */
 674         p = xdr_inline_decode(&stream, NFS4_DEVICEID4_SIZE + 20);
 675         if (unlikely(!p))
 676                 goto out_err;
 677
 678         memcpy(id, p, sizeof(*id));
 679         p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);
 680         nfs4_print_deviceid(id);
 681
 682         nfl_util = be32_to_cpup(p++);
 683         if (nfl_util & NFL4_UFLG_COMMIT_THRU_MDS)
 684                 fl->commit_through_mds = 1;
 685         if (nfl_util & NFL4_UFLG_DENSE)
 686                 fl->stripe_type = STRIPE_DENSE;
 687         else
 688                 fl->stripe_type = STRIPE_SPARSE;
 689         fl->stripe_unit = nfl_util & ~NFL4_UFLG_MASK;
 690
 691         fl->first_stripe_index = be32_to_cpup(p++);
 692         p = xdr_decode_hyper(p, &fl->pattern_offset);
 693         fl->num_fh = be32_to_cpup(p++);
 694
 695         dprintk("%s: nfl_util 0x%X num_fh %u fsi %u po %llu\n",
 696                 __func__, nfl_util, fl->num_fh, fl->first_stripe_index,
 697                 fl->pattern_offset);
 698
 699         /* Note that a zero value for num_fh is legal for STRIPE_SPARSE.
 700          * Futher checking is done in filelayout_check_layout */
 701         if (fl->num_fh >
 702             max(NFS4_PNFS_MAX_STRIPE_CNT, NFS4_PNFS_MAX_MULTI_CNT))
 703                 goto out_err;
 704
 705         if (fl->num_fh > 0) {
 706                 fl->fh_array = kcalloc(fl->num_fh, sizeof(fl->fh_array[0]),
 707                                        gfp_flags);
 708                 if (!fl->fh_array)
 709                         goto out_err;
 710         }
 711
 712         for (i = 0; i < fl->num_fh; i++) {
 713                 /* Do we want to use a mempool here? */
 714                 fl->fh_array[i] = kmalloc(sizeof(struct nfs_fh), gfp_flags);
 715                 if (!fl->fh_array[i])
 716                         goto out_err_free;
 717
 718                 p = xdr_inline_decode(&stream, 4);
 719                 if (unlikely(!p))
 720                         goto out_err_free;
 721                 fl->fh_array[i]->size = be32_to_cpup(p++);
 722                 if (sizeof(struct nfs_fh) < fl->fh_array[i]->size) {
 723                         printk(KERN_ERR "NFS: Too big fh %d received %d\n",
 724                                i, fl->fh_array[i]->size);
 725                         goto out_err_free;
 726                 }
 727
 728                 p = xdr_inline_decode(&stream, fl->fh_array[i]->size);
 729                 if (unlikely(!p))
 730                         goto out_err_free;
 731                 memcpy(fl->fh_array[i]->data, p, fl->fh_array[i]->size);
 732                 dprintk("DEBUG: %s: fh len %d\n", __func__,
 733                         fl->fh_array[i]->size);
 734         }
 735
 736         __free_page(scratch);
 737         return 0;
 738
 739 out_err_free:
 740         filelayout_free_fh_array(fl);
 741 out_err:
 742         __free_page(scratch);
 743         return -EIO;
 744 }
 745
 746 static void
 747 filelayout_free_lseg(struct pnfs_layout_segment *lseg)
 748 {
 749         struct nfs4_filelayout_segment *fl = FILELAYOUT_LSEG(lseg);
 750
 751         dprintk("--> %s\n", __func__);
 752         nfs4_fl_put_deviceid(fl->dsaddr);
 753         /* This assumes a single RW lseg */
 754         if (lseg->pls_range.iomode == IOMODE_RW) {
 755                 struct nfs4_filelayout *flo;
 756
 757                 flo = FILELAYOUT_FROM_HDR(lseg->pls_layout);
 758                 flo->commit_info.nbuckets = 0;
 759                 kfree(flo->commit_info.buckets);
 760                 flo->commit_info.buckets = NULL;
 761         }
 762         _filelayout_free_lseg(fl);
 763 }
 764
 765 static int
 766 filelayout_alloc_commit_info(struct pnfs_layout_segment *lseg,
 767                              struct nfs_commit_info *cinfo,
 768                              gfp_t gfp_flags)
 769 {
 770         struct nfs4_filelayout_segment *fl = FILELAYOUT_LSEG(lseg);
 771         struct pnfs_commit_bucket *buckets;
 772         int size, i;
 773
 774         if (fl->commit_through_mds)
 775                 return 0;
 776
 777         size = (fl->stripe_type == STRIPE_SPARSE) ?
 778                 fl->dsaddr->ds_num : fl->dsaddr->stripe_count;
 779
 780         if (cinfo->ds->nbuckets >= size) {
 781                 /* This assumes there is only one IOMODE_RW lseg.  What
 782                  * we really want to do is have a layout_hdr level
 783                  * dictionary of <multipath_list4, fh> keys, each
 784                  * associated with a struct list_head, populated by calls
 785                  * to filelayout_write_pagelist().
 786                  * */
 787                 return 0;
 788         }
 789
 790         buckets = kcalloc(size, sizeof(struct pnfs_commit_bucket),
 791                           gfp_flags);
 792         if (!buckets)
 793                 return -ENOMEM;
 794         for (i = 0; i < size; i++) {
 795                 INIT_LIST_HEAD(&buckets[i].written);
 796                 INIT_LIST_HEAD(&buckets[i].committing);
 797                 /* mark direct verifier as unset */
 798                 buckets[i].direct_verf.committed = NFS_INVALID_STABLE_HOW;
 799         }
 800
 801         spin_lock(cinfo->lock);
 802         if (cinfo->ds->nbuckets >= size)
 803                 goto out;
 804         for (i = 0; i < cinfo->ds->nbuckets; i++) {
 805                 list_splice(&cinfo->ds->buckets[i].written,
 806                             &buckets[i].written);
 807                 list_splice(&cinfo->ds->buckets[i].committing,
 808                             &buckets[i].committing);
 809                 buckets[i].direct_verf.committed =
 810                         cinfo->ds->buckets[i].direct_verf.committed;
 811                 buckets[i].wlseg = cinfo->ds->buckets[i].wlseg;
 812                 buckets[i].clseg = cinfo->ds->buckets[i].clseg;
 813         }
 814         swap(cinfo->ds->buckets, buckets);
 815         cinfo->ds->nbuckets = size;
 816 out:
 817         spin_unlock(cinfo->lock);
 818         kfree(buckets);
 819         return 0;
 820 }
 821
 822 static struct pnfs_layout_segment *
 823 filelayout_alloc_lseg(struct pnfs_layout_hdr *layoutid,
 824                       struct nfs4_layoutget_res *lgr,
 825                       gfp_t gfp_flags)
 826 {
 827         struct nfs4_filelayout_segment *fl;
 828         int rc;
 829         struct nfs4_deviceid id;
 830
 831         dprintk("--> %s\n", __func__);
 832         fl = kzalloc(sizeof(*fl), gfp_flags);
 833         if (!fl)
 834                 return NULL;
 835
 836         rc = filelayout_decode_layout(layoutid, fl, lgr, &id, gfp_flags);
 837         if (rc != 0 || filelayout_check_layout(layoutid, fl, lgr, &id, gfp_flags)) {
 838                 _filelayout_free_lseg(fl);
 839                 return NULL;
 840         }
 841         return &fl->generic_hdr;
 842 }
 843
 844 /*
 845  * filelayout_pg_test(). Called by nfs_can_coalesce_requests()
 846  *
 847  * Return 0 if @req cannot be coalesced into @pgio, otherwise return the number
 848  * of bytes (maximum @req->wb_bytes) that can be coalesced.
 849  */
 850 static size_t
 851 filelayout_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
 852                    struct nfs_page *req)
 853 {
 854         unsigned int size;
 855         u64 p_stripe, r_stripe;
 856         u32 stripe_offset;
 857         u64 segment_offset = pgio->pg_lseg->pls_range.offset;
 858         u32 stripe_unit = FILELAYOUT_LSEG(pgio->pg_lseg)->stripe_unit;
 859
 860         /* calls nfs_generic_pg_test */
 861         size = pnfs_generic_pg_test(pgio, prev, req);
 862         if (!size)
 863                 return 0;
 864
 865         /* see if req and prev are in the same stripe */
 866         if (prev) {
 867                 p_stripe = (u64)req_offset(prev) - segment_offset;
 868                 r_stripe = (u64)req_offset(req) - segment_offset;
 869                 do_div(p_stripe, stripe_unit);
 870                 do_div(r_stripe, stripe_unit);
 871
 872                 if (p_stripe != r_stripe)
 873                         return 0;
 874         }
 875
 876         /* calculate remaining bytes in the current stripe */
 877         div_u64_rem((u64)req_offset(req) - segment_offset,
 878                         stripe_unit,
 879                         &stripe_offset);
 880         WARN_ON_ONCE(stripe_offset > stripe_unit);
 881         if (stripe_offset >= stripe_unit)
 882                 return 0;
 883         return min(stripe_unit - (unsigned int)stripe_offset, size);
 884 }
 885
 886 static void
 887 filelayout_pg_init_read(struct nfs_pageio_descriptor *pgio,
 888                         struct nfs_page *req)
 889 {
 890         if (!pgio->pg_lseg)
 891                 pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
 892                                            req->wb_context,
 893                                            0,
 894                                            NFS4_MAX_UINT64,
 895                                            IOMODE_READ,
 896                                            GFP_KERNEL);
 897         /* If no lseg, fall back to read through mds */
 898         if (pgio->pg_lseg == NULL)
 899                 nfs_pageio_reset_read_mds(pgio);
 900 }
 901
 902 static void
 903 filelayout_pg_init_write(struct nfs_pageio_descriptor *pgio,
 904                          struct nfs_page *req)
 905 {
 906         struct nfs_commit_info cinfo;
 907         int status;
 908
 909         if (!pgio->pg_lseg)
 910                 pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
 911                                            req->wb_context,
 912                                            0,
 913                                            NFS4_MAX_UINT64,
 914                                            IOMODE_RW,
 915                                            GFP_NOFS);
 916         /* If no lseg, fall back to write through mds */
 917         if (pgio->pg_lseg == NULL)
 918                 goto out_mds;
 919         nfs_init_cinfo(&cinfo, pgio->pg_inode, pgio->pg_dreq);
 920         status = filelayout_alloc_commit_info(pgio->pg_lseg, &cinfo, GFP_NOFS);
 921         if (status < 0) {
 922                 pnfs_put_lseg(pgio->pg_lseg);
 923                 pgio->pg_lseg = NULL;
 924                 goto out_mds;
 925         }
 926         return;
 927 out_mds:
 928         nfs_pageio_reset_write_mds(pgio);
 929 }
 930
 931 static const struct nfs_pageio_ops filelayout_pg_read_ops = {
 932         .pg_init = filelayout_pg_init_read,
 933         .pg_test = filelayout_pg_test,
 934         .pg_doio = pnfs_generic_pg_readpages,
 935 };
 936
 937 static const struct nfs_pageio_ops filelayout_pg_write_ops = {
 938         .pg_init = filelayout_pg_init_write,
 939         .pg_test = filelayout_pg_test,
 940         .pg_doio = pnfs_generic_pg_writepages,
 941 };
 942
 943 static u32 select_bucket_index(struct nfs4_filelayout_segment *fl, u32 j)
 944 {
 945         if (fl->stripe_type == STRIPE_SPARSE)
 946                 return nfs4_fl_calc_ds_index(&fl->generic_hdr, j);
 947         else
 948                 return j;
 949 }
 950
 951 static void
 952 filelayout_mark_request_commit(struct nfs_page *req,
 953                                struct pnfs_layout_segment *lseg,
 954                                struct nfs_commit_info *cinfo)
 955
 956 {
 957         struct nfs4_filelayout_segment *fl = FILELAYOUT_LSEG(lseg);
 958         u32 i, j;
 959         struct list_head *list;
 960         struct pnfs_commit_bucket *buckets;
 961
 962         if (fl->commit_through_mds) {
 963                 list = &cinfo->mds->list;
 964                 spin_lock(cinfo->lock);
 965                 goto mds_commit;
 966         }
 967
 968         /* Note that we are calling nfs4_fl_calc_j_index on each page
 969          * that ends up being committed to a data server.  An attractive
 970          * alternative is to add a field to nfs_write_data and nfs_page
 971          * to store the value calculated in filelayout_write_pagelist
 972          * and just use that here.
 973          */
 974         j = nfs4_fl_calc_j_index(lseg, req_offset(req));
 975         i = select_bucket_index(fl, j);
 976         spin_lock(cinfo->lock);
 977         buckets = cinfo->ds->buckets;
 978         list = &buckets[i].written;
 979         if (list_empty(list)) {
 980                 /* Non-empty buckets hold a reference on the lseg.  That ref
 981                  * is normally transferred to the COMMIT call and released
 982                  * there.  It could also be released if the last req is pulled
 983                  * off due to a rewrite, in which case it will be done in
 984                  * pnfs_generic_clear_request_commit
 985                  */
 986                 buckets[i].wlseg = pnfs_get_lseg(lseg);
 987         }
 988         set_bit(PG_COMMIT_TO_DS, &req->wb_flags);
 989         cinfo->ds->nwritten++;
 990
 991 mds_commit:
 992         /* nfs_request_add_commit_list(). We need to add req to list without
 993          * dropping cinfo lock.
 994          */
 995         set_bit(PG_CLEAN, &(req)->wb_flags);
 996         nfs_list_add_request(req, list);
 997         cinfo->mds->ncommit++;
 998         spin_unlock(cinfo->lock);
 999         if (!cinfo->dreq) {
1000                 inc_zone_page_state(req->wb_page, NR_UNSTABLE_NFS);
1001                 inc_bdi_stat(page_file_mapping(req->wb_page)->backing_dev_info,
1002                              BDI_RECLAIMABLE);
1003                 __mark_inode_dirty(req->wb_context->dentry->d_inode,
1004                                    I_DIRTY_DATASYNC);
1005         }
1006 }
1007
1008 static u32 calc_ds_index_from_commit(struct pnfs_layout_segment *lseg, u32 i)
1009 {
1010         struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
1011
1012         if (flseg->stripe_type == STRIPE_SPARSE)
1013                 return i;
1014         else
1015                 return nfs4_fl_calc_ds_index(lseg, i);
1016 }
1017
1018 static struct nfs_fh *
1019 select_ds_fh_from_commit(struct pnfs_layout_segment *lseg, u32 i)
1020 {
1021         struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
1022
1023         if (flseg->stripe_type == STRIPE_SPARSE) {
1024                 if (flseg->num_fh == 1)
1025                         i = 0;
1026                 else if (flseg->num_fh == 0)
1027                         /* Use the MDS OPEN fh set in nfs_read_rpcsetup */
1028                         return NULL;
1029         }
1030         return flseg->fh_array[i];
1031 }
1032
1033 static int filelayout_initiate_commit(struct nfs_commit_data *data, int how)
1034 {
1035         struct pnfs_layout_segment *lseg = data->lseg;
1036         struct nfs4_pnfs_ds *ds;
1037         struct rpc_clnt *ds_clnt;
1038         u32 idx;
1039         struct nfs_fh *fh;
1040
1041         idx = calc_ds_index_from_commit(lseg, data->ds_commit_index);
1042         ds = nfs4_fl_prepare_ds(lseg, idx);
1043         if (!ds)
1044                 goto out_err;
1045
1046         ds_clnt = nfs4_find_or_create_ds_client(ds->ds_clp, data->inode);
1047         if (IS_ERR(ds_clnt))
1048                 goto out_err;
1049
1050         dprintk("%s ino %lu, how %d cl_count %d\n", __func__,
1051                 data->inode->i_ino, how, atomic_read(&ds->ds_clp->cl_count));
1052         data->commit_done_cb = filelayout_commit_done_cb;
1053         atomic_inc(&ds->ds_clp->cl_count);
1054         data->ds_clp = ds->ds_clp;
1055         fh = select_ds_fh_from_commit(lseg, data->ds_commit_index);
1056         if (fh)
1057                 data->args.fh = fh;
1058         return nfs_initiate_commit(ds_clnt, data,
1059                                    &filelayout_commit_call_ops, how,
1060                                    RPC_TASK_SOFTCONN);
1061 out_err:
1062         pnfs_generic_prepare_to_resend_writes(data);
1063         pnfs_generic_commit_release(data);
1064         return -EAGAIN;
1065 }
1066
1067 /* filelayout_search_commit_reqs - Search lists in @cinfo for the head reqest
1068  *                                 for @page
1069  * @cinfo - commit info for current inode
1070  * @page - page to search for matching head request
1071  *
1072  * Returns a the head request if one is found, otherwise returns NULL.
1073  */
1074 static struct nfs_page *
1075 filelayout_search_commit_reqs(struct nfs_commit_info *cinfo, struct page *page)
1076 {
1077         struct nfs_page *freq, *t;
1078         struct pnfs_commit_bucket *b;
1079         int i;
1080
1081         /* Linearly search the commit lists for each bucket until a matching
1082          * request is found */
1083         for (i = 0, b = cinfo->ds->buckets; i < cinfo->ds->nbuckets; i++, b++) {
1084                 list_for_each_entry_safe(freq, t, &b->written, wb_list) {
1085                         if (freq->wb_page == page)
1086                                 return freq->wb_head;
1087                 }
1088                 list_for_each_entry_safe(freq, t, &b->committing, wb_list) {
1089                         if (freq->wb_page == page)
1090                                 return freq->wb_head;
1091                 }
1092         }
1093
1094         return NULL;
1095 }
1096
1097 static int
1098 filelayout_commit_pagelist(struct inode *inode, struct list_head *mds_pages,
1099                            int how, struct nfs_commit_info *cinfo)
1100 {
1101         return pnfs_generic_commit_pagelist(inode, mds_pages, how, cinfo,
1102                                             filelayout_initiate_commit);
1103 }
1104
1105 static struct nfs4_deviceid_node *
1106 filelayout_alloc_deviceid_node(struct nfs_server *server,
1107                 struct pnfs_device *pdev, gfp_t gfp_flags)
1108 {
1109         struct nfs4_file_layout_dsaddr *dsaddr;
1110
1111         dsaddr = nfs4_fl_alloc_deviceid_node(server, pdev, gfp_flags);
1112         if (!dsaddr)
1113                 return NULL;
1114         return &dsaddr->id_node;
1115 }
1116
1117 static void
1118 filelayout_free_deveiceid_node(struct nfs4_deviceid_node *d)
1119 {
1120         nfs4_fl_free_deviceid(container_of(d, struct nfs4_file_layout_dsaddr, id_node));
1121 }
1122
1123 static struct pnfs_layout_hdr *
1124 filelayout_alloc_layout_hdr(struct inode *inode, gfp_t gfp_flags)
1125 {
1126         struct nfs4_filelayout *flo;
1127
1128         flo = kzalloc(sizeof(*flo), gfp_flags);
1129         return flo != NULL ? &flo->generic_hdr : NULL;
1130 }
1131
1132 static void
1133 filelayout_free_layout_hdr(struct pnfs_layout_hdr *lo)
1134 {
1135         kfree(FILELAYOUT_FROM_HDR(lo));
1136 }
1137
1138 static struct pnfs_ds_commit_info *
1139 filelayout_get_ds_info(struct inode *inode)
1140 {
1141         struct pnfs_layout_hdr *layout = NFS_I(inode)->layout;
1142
1143         if (layout == NULL)
1144                 return NULL;
1145         else
1146                 return &FILELAYOUT_FROM_HDR(layout)->commit_info;
1147 }
1148
1149 static struct pnfs_layoutdriver_type filelayout_type = {
1150         .id                     = LAYOUT_NFSV4_1_FILES,
1151         .name                   = "LAYOUT_NFSV4_1_FILES",
1152         .owner                  = THIS_MODULE,
1153         .alloc_layout_hdr       = filelayout_alloc_layout_hdr,
1154         .free_layout_hdr        = filelayout_free_layout_hdr,
1155         .alloc_lseg             = filelayout_alloc_lseg,
1156         .free_lseg              = filelayout_free_lseg,
1157         .pg_read_ops            = &filelayout_pg_read_ops,
1158         .pg_write_ops           = &filelayout_pg_write_ops,
1159         .get_ds_info            = &filelayout_get_ds_info,
1160         .mark_request_commit    = filelayout_mark_request_commit,
1161         .clear_request_commit   = pnfs_generic_clear_request_commit,
1162         .scan_commit_lists      = pnfs_generic_scan_commit_lists,
1163         .recover_commit_reqs    = pnfs_generic_recover_commit_reqs,
1164         .search_commit_reqs     = filelayout_search_commit_reqs,
1165         .commit_pagelist        = filelayout_commit_pagelist,
1166         .read_pagelist          = filelayout_read_pagelist,
1167         .write_pagelist         = filelayout_write_pagelist,
1168         .alloc_deviceid_node    = filelayout_alloc_deviceid_node,
1169         .free_deviceid_node     = filelayout_free_deveiceid_node,
1170 };
1171
1172 static int __init nfs4filelayout_init(void)
1173 {
1174         printk(KERN_INFO "%s: NFSv4 File Layout Driver Registering...\n",
1175                __func__);
1176         return pnfs_register_layoutdriver(&filelayout_type);
1177 }
1178
1179 static void __exit nfs4filelayout_exit(void)
1180 {
1181         printk(KERN_INFO "%s: NFSv4 File Layout Driver Unregistering...\n",
1182                __func__);
1183         pnfs_unregister_layoutdriver(&filelayout_type);
1184 }
1185
1186 MODULE_ALIAS("nfs-layouttype4-1");
1187
1188 module_init(nfs4filelayout_init);
1189 module_exit(nfs4filelayout_exit);