fs/nfs/nfs4filelayout.c

   1 /*
   2  *  Module for the pnfs nfs4 file layout driver.
   3  *  Defines all I/O and Policy interface operations, plus code
   4  *  to register itself with the pNFS client.
   5  *
   6  *  Copyright (c) 2002
   7  *  The Regents of the University of Michigan
   8  *  All Rights Reserved
   9  *
  10  *  Dean Hildebrand <dhildebz@umich.edu>
  11  *
  12  *  Permission is granted to use, copy, create derivative works, and
  13  *  redistribute this software and such derivative works for any purpose,
  14  *  so long as the name of the University of Michigan is not used in
  15  *  any advertising or publicity pertaining to the use or distribution
  16  *  of this software without specific, written prior authorization. If
  17  *  the above copyright notice or any other identification of the
  18  *  University of Michigan is included in any copy of any portion of
  19  *  this software, then the disclaimer below must also be included.
  20  *
  21  *  This software is provided as is, without representation or warranty
  22  *  of any kind either express or implied, including without limitation
  23  *  the implied warranties of merchantability, fitness for a particular
  24  *  purpose, or noninfringement.  The Regents of the University of
  25  *  Michigan shall not be liable for any damages, including special,
  26  *  indirect, incidental, or consequential damages, with respect to any
  27  *  claim arising out of or in connection with the use of the software,
  28  *  even if it has been or is hereafter advised of the possibility of
  29  *  such damages.
  30  */
  31
  32 #include <linux/nfs_fs.h>
  33 #include <linux/nfs_page.h>
  34 #include <linux/module.h>
  35
  36 #include <linux/sunrpc/metrics.h>
  37
  38 #include "nfs4session.h"
  39 #include "internal.h"
  40 #include "delegation.h"
  41 #include "nfs4filelayout.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_write_data *data)
  88 {
  89         struct nfs_pgio_header *hdr = data->header;
  90         struct rpc_task *task = &data->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                         data->task.tk_pid,
  96                         hdr->inode->i_sb->s_id,
  97                         (unsigned long long)NFS_FILEID(hdr->inode),
  98                         data->args.count,
  99                         (unsigned long long)data->args.offset);
 100
 101                 task->tk_status = pnfs_write_done_resend_to_mds(hdr->inode,
 102                                                         &hdr->pages,
 103                                                         hdr->completion_ops,
 104                                                         hdr->dreq);
 105         }
 106 }
 107
 108 static void filelayout_reset_read(struct nfs_read_data *data)
 109 {
 110         struct nfs_pgio_header *hdr = data->header;
 111         struct rpc_task *task = &data->task;
 112
 113         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
 114                 dprintk("%s Reset task %5u for i/o through MDS "
 115                         "(req %s/%llu, %u bytes @ offset %llu)\n", __func__,
 116                         data->task.tk_pid,
 117                         hdr->inode->i_sb->s_id,
 118                         (unsigned long long)NFS_FILEID(hdr->inode),
 119                         data->args.count,
 120                         (unsigned long long)data->args.offset);
 121
 122                 task->tk_status = pnfs_read_done_resend_to_mds(hdr->inode,
 123                                                         &hdr->pages,
 124                                                         hdr->completion_ops,
 125                                                         hdr->dreq);
 126         }
 127 }
 128
 129 static void filelayout_fenceme(struct inode *inode, struct pnfs_layout_hdr *lo)
 130 {
 131         if (!test_and_clear_bit(NFS_LAYOUT_RETURN, &lo->plh_flags))
 132                 return;
 133         pnfs_return_layout(inode);
 134 }
 135
 136 static int filelayout_async_handle_error(struct rpc_task *task,
 137                                          struct nfs4_state *state,
 138                                          struct nfs_client *clp,
 139                                          struct pnfs_layout_segment *lseg)
 140 {
 141         struct pnfs_layout_hdr *lo = lseg->pls_layout;
 142         struct inode *inode = lo->plh_inode;
 143         struct nfs_server *mds_server = NFS_SERVER(inode);
 144         struct nfs4_deviceid_node *devid = FILELAYOUT_DEVID_NODE(lseg);
 145         struct nfs_client *mds_client = mds_server->nfs_client;
 146         struct nfs4_slot_table *tbl = &clp->cl_session->fc_slot_table;
 147
 148         if (task->tk_status >= 0)
 149                 return 0;
 150
 151         switch (task->tk_status) {
 152         /* MDS state errors */
 153         case -NFS4ERR_DELEG_REVOKED:
 154         case -NFS4ERR_ADMIN_REVOKED:
 155         case -NFS4ERR_BAD_STATEID:
 156                 if (state == NULL)
 157                         break;
 158                 nfs_remove_bad_delegation(state->inode);
 159         case -NFS4ERR_OPENMODE:
 160                 if (state == NULL)
 161                         break;
 162                 if (nfs4_schedule_stateid_recovery(mds_server, state) < 0)
 163                         goto out_bad_stateid;
 164                 goto wait_on_recovery;
 165         case -NFS4ERR_EXPIRED:
 166                 if (state != NULL) {
 167                         if (nfs4_schedule_stateid_recovery(mds_server, state) < 0)
 168                                 goto out_bad_stateid;
 169                 }
 170                 nfs4_schedule_lease_recovery(mds_client);
 171                 goto wait_on_recovery;
 172         /* DS session errors */
 173         case -NFS4ERR_BADSESSION:
 174         case -NFS4ERR_BADSLOT:
 175         case -NFS4ERR_BAD_HIGH_SLOT:
 176         case -NFS4ERR_DEADSESSION:
 177         case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
 178         case -NFS4ERR_SEQ_FALSE_RETRY:
 179         case -NFS4ERR_SEQ_MISORDERED:
 180                 dprintk("%s ERROR %d, Reset session. Exchangeid "
 181                         "flags 0x%x\n", __func__, task->tk_status,
 182                         clp->cl_exchange_flags);
 183                 nfs4_schedule_session_recovery(clp->cl_session, task->tk_status);
 184                 break;
 185         case -NFS4ERR_DELAY:
 186         case -NFS4ERR_GRACE:
 187                 rpc_delay(task, FILELAYOUT_POLL_RETRY_MAX);
 188                 break;
 189         case -NFS4ERR_RETRY_UNCACHED_REP:
 190                 break;
 191         /* Invalidate Layout errors */
 192         case -NFS4ERR_PNFS_NO_LAYOUT:
 193         case -ESTALE:           /* mapped NFS4ERR_STALE */
 194         case -EBADHANDLE:       /* mapped NFS4ERR_BADHANDLE */
 195         case -EISDIR:           /* mapped NFS4ERR_ISDIR */
 196         case -NFS4ERR_FHEXPIRED:
 197         case -NFS4ERR_WRONG_TYPE:
 198                 dprintk("%s Invalid layout error %d\n", __func__,
 199                         task->tk_status);
 200                 /*
 201                  * Destroy layout so new i/o will get a new layout.
 202                  * Layout will not be destroyed until all current lseg
 203                  * references are put. Mark layout as invalid to resend failed
 204                  * i/o and all i/o waiting on the slot table to the MDS until
 205                  * layout is destroyed and a new valid layout is obtained.
 206                  */
 207                 pnfs_destroy_layout(NFS_I(inode));
 208                 rpc_wake_up(&tbl->slot_tbl_waitq);
 209                 goto reset;
 210         /* RPC connection errors */
 211         case -ECONNREFUSED:
 212         case -EHOSTDOWN:
 213         case -EHOSTUNREACH:
 214         case -ENETUNREACH:
 215         case -EIO:
 216         case -ETIMEDOUT:
 217         case -EPIPE:
 218                 dprintk("%s DS connection error %d\n", __func__,
 219                         task->tk_status);
 220                 nfs4_mark_deviceid_unavailable(devid);
 221                 set_bit(NFS_LAYOUT_RETURN, &lo->plh_flags);
 222                 rpc_wake_up(&tbl->slot_tbl_waitq);
 223                 /* fall through */
 224         default:
 225 reset:
 226                 dprintk("%s Retry through MDS. Error %d\n", __func__,
 227                         task->tk_status);
 228                 return -NFS4ERR_RESET_TO_MDS;
 229         }
 230 out:
 231         task->tk_status = 0;
 232         return -EAGAIN;
 233 out_bad_stateid:
 234         task->tk_status = -EIO;
 235         return 0;
 236 wait_on_recovery:
 237         rpc_sleep_on(&mds_client->cl_rpcwaitq, task, NULL);
 238         if (test_bit(NFS4CLNT_MANAGER_RUNNING, &mds_client->cl_state) == 0)
 239                 rpc_wake_up_queued_task(&mds_client->cl_rpcwaitq, task);
 240         goto out;
 241 }
 242
 243 /* NFS_PROTO call done callback routines */
 244
 245 static int filelayout_read_done_cb(struct rpc_task *task,
 246                                 struct nfs_read_data *data)
 247 {
 248         struct nfs_pgio_header *hdr = data->header;
 249         int err;
 250
 251         trace_nfs4_pnfs_read(data, task->tk_status);
 252         err = filelayout_async_handle_error(task, data->args.context->state,
 253                                             data->ds_clp, hdr->lseg);
 254
 255         switch (err) {
 256         case -NFS4ERR_RESET_TO_MDS:
 257                 filelayout_reset_read(data);
 258                 return task->tk_status;
 259         case -EAGAIN:
 260                 rpc_restart_call_prepare(task);
 261                 return -EAGAIN;
 262         }
 263
 264         return 0;
 265 }
 266
 267 /*
 268  * We reference the rpc_cred of the first WRITE that triggers the need for
 269  * a LAYOUTCOMMIT, and use it to send the layoutcommit compound.
 270  * rfc5661 is not clear about which credential should be used.
 271  */
 272 static void
 273 filelayout_set_layoutcommit(struct nfs_write_data *wdata)
 274 {
 275         struct nfs_pgio_header *hdr = wdata->header;
 276
 277         if (FILELAYOUT_LSEG(hdr->lseg)->commit_through_mds ||
 278             wdata->res.verf->committed == NFS_FILE_SYNC)
 279                 return;
 280
 281         pnfs_set_layoutcommit(wdata);
 282         dprintk("%s ionde %lu pls_end_pos %lu\n", __func__, hdr->inode->i_ino,
 283                 (unsigned long) NFS_I(hdr->inode)->layout->plh_lwb);
 284 }
 285
 286 bool
 287 filelayout_test_devid_unavailable(struct nfs4_deviceid_node *node)
 288 {
 289         return filelayout_test_devid_invalid(node) ||
 290                 nfs4_test_deviceid_unavailable(node);
 291 }
 292
 293 static bool
 294 filelayout_reset_to_mds(struct pnfs_layout_segment *lseg)
 295 {
 296         struct nfs4_deviceid_node *node = FILELAYOUT_DEVID_NODE(lseg);
 297
 298         return filelayout_test_devid_unavailable(node);
 299 }
 300
 301 /*
 302  * Call ops for the async read/write cases
 303  * In the case of dense layouts, the offset needs to be reset to its
 304  * original value.
 305  */
 306 static void filelayout_read_prepare(struct rpc_task *task, void *data)
 307 {
 308         struct nfs_read_data *rdata = data;
 309
 310         if (unlikely(test_bit(NFS_CONTEXT_BAD, &rdata->args.context->flags))) {
 311                 rpc_exit(task, -EIO);
 312                 return;
 313         }
 314         if (filelayout_reset_to_mds(rdata->header->lseg)) {
 315                 dprintk("%s task %u reset io to MDS\n", __func__, task->tk_pid);
 316                 filelayout_reset_read(rdata);
 317                 rpc_exit(task, 0);
 318                 return;
 319         }
 320         rdata->read_done_cb = filelayout_read_done_cb;
 321
 322         if (nfs41_setup_sequence(rdata->ds_clp->cl_session,
 323                         &rdata->args.seq_args,
 324                         &rdata->res.seq_res,
 325                         task))
 326                 return;
 327         nfs4_set_rw_stateid(&rdata->args.stateid, rdata->args.context,
 328                         rdata->args.lock_context, FMODE_READ);
 329 }
 330
 331 static void filelayout_read_call_done(struct rpc_task *task, void *data)
 332 {
 333         struct nfs_read_data *rdata = data;
 334
 335         dprintk("--> %s task->tk_status %d\n", __func__, task->tk_status);
 336
 337         if (test_bit(NFS_IOHDR_REDO, &rdata->header->flags) &&
 338             task->tk_status == 0) {
 339                 nfs41_sequence_done(task, &rdata->res.seq_res);
 340                 return;
 341         }
 342
 343         /* Note this may cause RPC to be resent */
 344         rdata->header->mds_ops->rpc_call_done(task, data);
 345 }
 346
 347 static void filelayout_read_count_stats(struct rpc_task *task, void *data)
 348 {
 349         struct nfs_read_data *rdata = data;
 350
 351         rpc_count_iostats(task, NFS_SERVER(rdata->header->inode)->client->cl_metrics);
 352 }
 353
 354 static void filelayout_read_release(void *data)
 355 {
 356         struct nfs_read_data *rdata = data;
 357         struct pnfs_layout_hdr *lo = rdata->header->lseg->pls_layout;
 358
 359         filelayout_fenceme(lo->plh_inode, lo);
 360         nfs_put_client(rdata->ds_clp);
 361         rdata->header->mds_ops->rpc_release(data);
 362 }
 363
 364 static int filelayout_write_done_cb(struct rpc_task *task,
 365                                 struct nfs_write_data *data)
 366 {
 367         struct nfs_pgio_header *hdr = data->header;
 368         int err;
 369
 370         trace_nfs4_pnfs_write(data, task->tk_status);
 371         err = filelayout_async_handle_error(task, data->args.context->state,
 372                                             data->ds_clp, hdr->lseg);
 373
 374         switch (err) {
 375         case -NFS4ERR_RESET_TO_MDS:
 376                 filelayout_reset_write(data);
 377                 return task->tk_status;
 378         case -EAGAIN:
 379                 rpc_restart_call_prepare(task);
 380                 return -EAGAIN;
 381         }
 382
 383         filelayout_set_layoutcommit(data);
 384         return 0;
 385 }
 386
 387 /* Fake up some data that will cause nfs_commit_release to retry the writes. */
 388 static void prepare_to_resend_writes(struct nfs_commit_data *data)
 389 {
 390         struct nfs_page *first = nfs_list_entry(data->pages.next);
 391
 392         data->task.tk_status = 0;
 393         memcpy(&data->verf.verifier, &first->wb_verf,
 394                sizeof(data->verf.verifier));
 395         data->verf.verifier.data[0]++; /* ensure verifier mismatch */
 396 }
 397
 398 static int filelayout_commit_done_cb(struct rpc_task *task,
 399                                      struct nfs_commit_data *data)
 400 {
 401         int err;
 402
 403         trace_nfs4_pnfs_commit_ds(data, task->tk_status);
 404         err = filelayout_async_handle_error(task, NULL, data->ds_clp,
 405                                             data->lseg);
 406
 407         switch (err) {
 408         case -NFS4ERR_RESET_TO_MDS:
 409                 prepare_to_resend_writes(data);
 410                 return -EAGAIN;
 411         case -EAGAIN:
 412                 rpc_restart_call_prepare(task);
 413                 return -EAGAIN;
 414         }
 415
 416         return 0;
 417 }
 418
 419 static void filelayout_write_prepare(struct rpc_task *task, void *data)
 420 {
 421         struct nfs_write_data *wdata = data;
 422
 423         if (unlikely(test_bit(NFS_CONTEXT_BAD, &wdata->args.context->flags))) {
 424                 rpc_exit(task, -EIO);
 425                 return;
 426         }
 427         if (filelayout_reset_to_mds(wdata->header->lseg)) {
 428                 dprintk("%s task %u reset io to MDS\n", __func__, task->tk_pid);
 429                 filelayout_reset_write(wdata);
 430                 rpc_exit(task, 0);
 431                 return;
 432         }
 433         if (nfs41_setup_sequence(wdata->ds_clp->cl_session,
 434                         &wdata->args.seq_args,
 435                         &wdata->res.seq_res,
 436                         task))
 437                 return;
 438         nfs4_set_rw_stateid(&wdata->args.stateid, wdata->args.context,
 439                         wdata->args.lock_context, FMODE_WRITE);
 440 }
 441
 442 static void filelayout_write_call_done(struct rpc_task *task, void *data)
 443 {
 444         struct nfs_write_data *wdata = data;
 445
 446         if (test_bit(NFS_IOHDR_REDO, &wdata->header->flags) &&
 447             task->tk_status == 0) {
 448                 nfs41_sequence_done(task, &wdata->res.seq_res);
 449                 return;
 450         }
 451
 452         /* Note this may cause RPC to be resent */
 453         wdata->header->mds_ops->rpc_call_done(task, data);
 454 }
 455
 456 static void filelayout_write_count_stats(struct rpc_task *task, void *data)
 457 {
 458         struct nfs_write_data *wdata = data;
 459
 460         rpc_count_iostats(task, NFS_SERVER(wdata->header->inode)->client->cl_metrics);
 461 }
 462
 463 static void filelayout_write_release(void *data)
 464 {
 465         struct nfs_write_data *wdata = data;
 466         struct pnfs_layout_hdr *lo = wdata->header->lseg->pls_layout;
 467
 468         filelayout_fenceme(lo->plh_inode, lo);
 469         nfs_put_client(wdata->ds_clp);
 470         wdata->header->mds_ops->rpc_release(data);
 471 }
 472
 473 static void filelayout_commit_prepare(struct rpc_task *task, void *data)
 474 {
 475         struct nfs_commit_data *wdata = data;
 476
 477         nfs41_setup_sequence(wdata->ds_clp->cl_session,
 478                         &wdata->args.seq_args,
 479                         &wdata->res.seq_res,
 480                         task);
 481 }
 482
 483 static void filelayout_write_commit_done(struct rpc_task *task, void *data)
 484 {
 485         struct nfs_commit_data *wdata = data;
 486
 487         /* Note this may cause RPC to be resent */
 488         wdata->mds_ops->rpc_call_done(task, data);
 489 }
 490
 491 static void filelayout_commit_count_stats(struct rpc_task *task, void *data)
 492 {
 493         struct nfs_commit_data *cdata = data;
 494
 495         rpc_count_iostats(task, NFS_SERVER(cdata->inode)->client->cl_metrics);
 496 }
 497
 498 static void filelayout_commit_release(void *calldata)
 499 {
 500         struct nfs_commit_data *data = calldata;
 501
 502         data->completion_ops->completion(data);
 503         pnfs_put_lseg(data->lseg);
 504         nfs_put_client(data->ds_clp);
 505         nfs_commitdata_release(data);
 506 }
 507
 508 static const struct rpc_call_ops filelayout_read_call_ops = {
 509         .rpc_call_prepare = filelayout_read_prepare,
 510         .rpc_call_done = filelayout_read_call_done,
 511         .rpc_count_stats = filelayout_read_count_stats,
 512         .rpc_release = filelayout_read_release,
 513 };
 514
 515 static const struct rpc_call_ops filelayout_write_call_ops = {
 516         .rpc_call_prepare = filelayout_write_prepare,
 517         .rpc_call_done = filelayout_write_call_done,
 518         .rpc_count_stats = filelayout_write_count_stats,
 519         .rpc_release = filelayout_write_release,
 520 };
 521
 522 static const struct rpc_call_ops filelayout_commit_call_ops = {
 523         .rpc_call_prepare = filelayout_commit_prepare,
 524         .rpc_call_done = filelayout_write_commit_done,
 525         .rpc_count_stats = filelayout_commit_count_stats,
 526         .rpc_release = filelayout_commit_release,
 527 };
 528
 529 static enum pnfs_try_status
 530 filelayout_read_pagelist(struct nfs_read_data *data)
 531 {
 532         struct nfs_pgio_header *hdr = data->header;
 533         struct pnfs_layout_segment *lseg = hdr->lseg;
 534         struct nfs4_pnfs_ds *ds;
 535         struct rpc_clnt *ds_clnt;
 536         loff_t offset = data->args.offset;
 537         u32 j, idx;
 538         struct nfs_fh *fh;
 539
 540         dprintk("--> %s ino %lu pgbase %u req %Zu@%llu\n",
 541                 __func__, hdr->inode->i_ino,
 542                 data->args.pgbase, (size_t)data->args.count, offset);
 543
 544         /* Retrieve the correct rpc_client for the byte range */
 545         j = nfs4_fl_calc_j_index(lseg, offset);
 546         idx = nfs4_fl_calc_ds_index(lseg, j);
 547         ds = nfs4_fl_prepare_ds(lseg, idx);
 548         if (!ds)
 549                 return PNFS_NOT_ATTEMPTED;
 550
 551         ds_clnt = nfs4_find_or_create_ds_client(ds->ds_clp, hdr->inode);
 552         if (IS_ERR(ds_clnt))
 553                 return PNFS_NOT_ATTEMPTED;
 554
 555         dprintk("%s USE DS: %s cl_count %d\n", __func__,
 556                 ds->ds_remotestr, atomic_read(&ds->ds_clp->cl_count));
 557
 558         /* No multipath support. Use first DS */
 559         atomic_inc(&ds->ds_clp->cl_count);
 560         data->ds_clp = ds->ds_clp;
 561         fh = nfs4_fl_select_ds_fh(lseg, j);
 562         if (fh)
 563                 data->args.fh = fh;
 564
 565         data->args.offset = filelayout_get_dserver_offset(lseg, offset);
 566         data->mds_offset = offset;
 567
 568         /* Perform an asynchronous read to ds */
 569         nfs_initiate_read(ds_clnt, data,
 570                                   &filelayout_read_call_ops, RPC_TASK_SOFTCONN);
 571         return PNFS_ATTEMPTED;
 572 }
 573
 574 /* Perform async writes. */
 575 static enum pnfs_try_status
 576 filelayout_write_pagelist(struct nfs_write_data *data, int sync)
 577 {
 578         struct nfs_pgio_header *hdr = data->header;
 579         struct pnfs_layout_segment *lseg = hdr->lseg;
 580         struct nfs4_pnfs_ds *ds;
 581         struct rpc_clnt *ds_clnt;
 582         loff_t offset = data->args.offset;
 583         u32 j, idx;
 584         struct nfs_fh *fh;
 585
 586         /* Retrieve the correct rpc_client for the byte range */
 587         j = nfs4_fl_calc_j_index(lseg, offset);
 588         idx = nfs4_fl_calc_ds_index(lseg, j);
 589         ds = nfs4_fl_prepare_ds(lseg, idx);
 590         if (!ds)
 591                 return PNFS_NOT_ATTEMPTED;
 592
 593         ds_clnt = nfs4_find_or_create_ds_client(ds->ds_clp, hdr->inode);
 594         if (IS_ERR(ds_clnt))
 595                 return PNFS_NOT_ATTEMPTED;
 596
 597         dprintk("%s ino %lu sync %d req %Zu@%llu DS: %s cl_count %d\n",
 598                 __func__, hdr->inode->i_ino, sync, (size_t) data->args.count,
 599                 offset, ds->ds_remotestr, atomic_read(&ds->ds_clp->cl_count));
 600
 601         data->write_done_cb = filelayout_write_done_cb;
 602         atomic_inc(&ds->ds_clp->cl_count);
 603         data->ds_clp = ds->ds_clp;
 604         fh = nfs4_fl_select_ds_fh(lseg, j);
 605         if (fh)
 606                 data->args.fh = fh;
 607         /*
 608          * Get the file offset on the dserver. Set the write offset to
 609          * this offset and save the original offset.
 610          */
 611         data->args.offset = filelayout_get_dserver_offset(lseg, offset);
 612
 613         /* Perform an asynchronous write */
 614         nfs_initiate_write(ds_clnt, data,
 615                                     &filelayout_write_call_ops, sync,
 616                                     RPC_TASK_SOFTCONN);
 617         return PNFS_ATTEMPTED;
 618 }
 619
 620 /*
 621  * filelayout_check_layout()
 622  *
 623  * Make sure layout segment parameters are sane WRT the device.
 624  * At this point no generic layer initialization of the lseg has occurred,
 625  * and nothing has been added to the layout_hdr cache.
 626  *
 627  */
 628 static int
 629 filelayout_check_layout(struct pnfs_layout_hdr *lo,
 630                         struct nfs4_filelayout_segment *fl,
 631                         struct nfs4_layoutget_res *lgr,
 632                         struct nfs4_deviceid *id,
 633                         gfp_t gfp_flags)
 634 {
 635         struct nfs4_deviceid_node *d;
 636         struct nfs4_file_layout_dsaddr *dsaddr;
 637         int status = -EINVAL;
 638         struct nfs_server *nfss = NFS_SERVER(lo->plh_inode);
 639
 640         dprintk("--> %s\n", __func__);
 641
 642         /* FIXME: remove this check when layout segment support is added */
 643         if (lgr->range.offset != 0 ||
 644             lgr->range.length != NFS4_MAX_UINT64) {
 645                 dprintk("%s Only whole file layouts supported. Use MDS i/o\n",
 646                         __func__);
 647                 goto out;
 648         }
 649
 650         if (fl->pattern_offset > lgr->range.offset) {
 651                 dprintk("%s pattern_offset %lld too large\n",
 652                                 __func__, fl->pattern_offset);
 653                 goto out;
 654         }
 655
 656         if (!fl->stripe_unit || fl->stripe_unit % PAGE_SIZE) {
 657                 dprintk("%s Invalid stripe unit (%u)\n",
 658                         __func__, fl->stripe_unit);
 659                 goto out;
 660         }
 661
 662         /* find and reference the deviceid */
 663         d = nfs4_find_get_deviceid(NFS_SERVER(lo->plh_inode)->pnfs_curr_ld,
 664                                    NFS_SERVER(lo->plh_inode)->nfs_client, id);
 665         if (d == NULL) {
 666                 dsaddr = filelayout_get_device_info(lo->plh_inode, id,
 667                                 lo->plh_lc_cred, gfp_flags);
 668                 if (dsaddr == NULL)
 669                         goto out;
 670         } else
 671                 dsaddr = container_of(d, struct nfs4_file_layout_dsaddr, id_node);
 672         /* Found deviceid is unavailable */
 673         if (filelayout_test_devid_unavailable(&dsaddr->id_node))
 674                         goto out_put;
 675
 676         fl->dsaddr = dsaddr;
 677
 678         if (fl->first_stripe_index >= dsaddr->stripe_count) {
 679                 dprintk("%s Bad first_stripe_index %u\n",
 680                                 __func__, fl->first_stripe_index);
 681                 goto out_put;
 682         }
 683
 684         if ((fl->stripe_type == STRIPE_SPARSE &&
 685             fl->num_fh > 1 && fl->num_fh != dsaddr->ds_num) ||
 686             (fl->stripe_type == STRIPE_DENSE &&
 687             fl->num_fh != dsaddr->stripe_count)) {
 688                 dprintk("%s num_fh %u not valid for given packing\n",
 689                         __func__, fl->num_fh);
 690                 goto out_put;
 691         }
 692
 693         if (fl->stripe_unit % nfss->rsize || fl->stripe_unit % nfss->wsize) {
 694                 dprintk("%s Stripe unit (%u) not aligned with rsize %u "
 695                         "wsize %u\n", __func__, fl->stripe_unit, nfss->rsize,
 696                         nfss->wsize);
 697         }
 698
 699         status = 0;
 700 out:
 701         dprintk("--> %s returns %d\n", __func__, status);
 702         return status;
 703 out_put:
 704         nfs4_fl_put_deviceid(dsaddr);
 705         goto out;
 706 }
 707
 708 static void filelayout_free_fh_array(struct nfs4_filelayout_segment *fl)
 709 {
 710         int i;
 711
 712         for (i = 0; i < fl->num_fh; i++) {
 713                 if (!fl->fh_array[i])
 714                         break;
 715                 kfree(fl->fh_array[i]);
 716         }
 717         kfree(fl->fh_array);
 718         fl->fh_array = NULL;
 719 }
 720
 721 static void
 722 _filelayout_free_lseg(struct nfs4_filelayout_segment *fl)
 723 {
 724         filelayout_free_fh_array(fl);
 725         kfree(fl);
 726 }
 727
 728 static int
 729 filelayout_decode_layout(struct pnfs_layout_hdr *flo,
 730                          struct nfs4_filelayout_segment *fl,
 731                          struct nfs4_layoutget_res *lgr,
 732                          struct nfs4_deviceid *id,
 733                          gfp_t gfp_flags)
 734 {
 735         struct xdr_stream stream;
 736         struct xdr_buf buf;
 737         struct page *scratch;
 738         __be32 *p;
 739         uint32_t nfl_util;
 740         int i;
 741
 742         dprintk("%s: set_layout_map Begin\n", __func__);
 743
 744         scratch = alloc_page(gfp_flags);
 745         if (!scratch)
 746                 return -ENOMEM;
 747
 748         xdr_init_decode_pages(&stream, &buf, lgr->layoutp->pages, lgr->layoutp->len);
 749         xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
 750
 751         /* 20 = ufl_util (4), first_stripe_index (4), pattern_offset (8),
 752          * num_fh (4) */
 753         p = xdr_inline_decode(&stream, NFS4_DEVICEID4_SIZE + 20);
 754         if (unlikely(!p))
 755                 goto out_err;
 756
 757         memcpy(id, p, sizeof(*id));
 758         p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);
 759         nfs4_print_deviceid(id);
 760
 761         nfl_util = be32_to_cpup(p++);
 762         if (nfl_util & NFL4_UFLG_COMMIT_THRU_MDS)
 763                 fl->commit_through_mds = 1;
 764         if (nfl_util & NFL4_UFLG_DENSE)
 765                 fl->stripe_type = STRIPE_DENSE;
 766         else
 767                 fl->stripe_type = STRIPE_SPARSE;
 768         fl->stripe_unit = nfl_util & ~NFL4_UFLG_MASK;
 769
 770         fl->first_stripe_index = be32_to_cpup(p++);
 771         p = xdr_decode_hyper(p, &fl->pattern_offset);
 772         fl->num_fh = be32_to_cpup(p++);
 773
 774         dprintk("%s: nfl_util 0x%X num_fh %u fsi %u po %llu\n",
 775                 __func__, nfl_util, fl->num_fh, fl->first_stripe_index,
 776                 fl->pattern_offset);
 777
 778         /* Note that a zero value for num_fh is legal for STRIPE_SPARSE.
 779          * Futher checking is done in filelayout_check_layout */
 780         if (fl->num_fh >
 781             max(NFS4_PNFS_MAX_STRIPE_CNT, NFS4_PNFS_MAX_MULTI_CNT))
 782                 goto out_err;
 783
 784         if (fl->num_fh > 0) {
 785                 fl->fh_array = kcalloc(fl->num_fh, sizeof(fl->fh_array[0]),
 786                                        gfp_flags);
 787                 if (!fl->fh_array)
 788                         goto out_err;
 789         }
 790
 791         for (i = 0; i < fl->num_fh; i++) {
 792                 /* Do we want to use a mempool here? */
 793                 fl->fh_array[i] = kmalloc(sizeof(struct nfs_fh), gfp_flags);
 794                 if (!fl->fh_array[i])
 795                         goto out_err_free;
 796
 797                 p = xdr_inline_decode(&stream, 4);
 798                 if (unlikely(!p))
 799                         goto out_err_free;
 800                 fl->fh_array[i]->size = be32_to_cpup(p++);
 801                 if (sizeof(struct nfs_fh) < fl->fh_array[i]->size) {
 802                         printk(KERN_ERR "NFS: Too big fh %d received %d\n",
 803                                i, fl->fh_array[i]->size);
 804                         goto out_err_free;
 805                 }
 806
 807                 p = xdr_inline_decode(&stream, fl->fh_array[i]->size);
 808                 if (unlikely(!p))
 809                         goto out_err_free;
 810                 memcpy(fl->fh_array[i]->data, p, fl->fh_array[i]->size);
 811                 dprintk("DEBUG: %s: fh len %d\n", __func__,
 812                         fl->fh_array[i]->size);
 813         }
 814
 815         __free_page(scratch);
 816         return 0;
 817
 818 out_err_free:
 819         filelayout_free_fh_array(fl);
 820 out_err:
 821         __free_page(scratch);
 822         return -EIO;
 823 }
 824
 825 static void
 826 filelayout_free_lseg(struct pnfs_layout_segment *lseg)
 827 {
 828         struct nfs4_filelayout_segment *fl = FILELAYOUT_LSEG(lseg);
 829
 830         dprintk("--> %s\n", __func__);
 831         nfs4_fl_put_deviceid(fl->dsaddr);
 832         /* This assumes a single RW lseg */
 833         if (lseg->pls_range.iomode == IOMODE_RW) {
 834                 struct nfs4_filelayout *flo;
 835
 836                 flo = FILELAYOUT_FROM_HDR(lseg->pls_layout);
 837                 flo->commit_info.nbuckets = 0;
 838                 kfree(flo->commit_info.buckets);
 839                 flo->commit_info.buckets = NULL;
 840         }
 841         _filelayout_free_lseg(fl);
 842 }
 843
 844 static int
 845 filelayout_alloc_commit_info(struct pnfs_layout_segment *lseg,
 846                              struct nfs_commit_info *cinfo,
 847                              gfp_t gfp_flags)
 848 {
 849         struct nfs4_filelayout_segment *fl = FILELAYOUT_LSEG(lseg);
 850         struct pnfs_commit_bucket *buckets;
 851         int size;
 852
 853         if (fl->commit_through_mds)
 854                 return 0;
 855         if (cinfo->ds->nbuckets != 0) {
 856                 /* This assumes there is only one IOMODE_RW lseg.  What
 857                  * we really want to do is have a layout_hdr level
 858                  * dictionary of <multipath_list4, fh> keys, each
 859                  * associated with a struct list_head, populated by calls
 860                  * to filelayout_write_pagelist().
 861                  * */
 862                 return 0;
 863         }
 864
 865         size = (fl->stripe_type == STRIPE_SPARSE) ?
 866                 fl->dsaddr->ds_num : fl->dsaddr->stripe_count;
 867
 868         buckets = kcalloc(size, sizeof(struct pnfs_commit_bucket),
 869                           gfp_flags);
 870         if (!buckets)
 871                 return -ENOMEM;
 872         else {
 873                 int i;
 874
 875                 spin_lock(cinfo->lock);
 876                 if (cinfo->ds->nbuckets != 0)
 877                         kfree(buckets);
 878                 else {
 879                         cinfo->ds->buckets = buckets;
 880                         cinfo->ds->nbuckets = size;
 881                         for (i = 0; i < size; i++) {
 882                                 INIT_LIST_HEAD(&buckets[i].written);
 883                                 INIT_LIST_HEAD(&buckets[i].committing);
 884                         }
 885                 }
 886                 spin_unlock(cinfo->lock);
 887                 return 0;
 888         }
 889 }
 890
 891 static struct pnfs_layout_segment *
 892 filelayout_alloc_lseg(struct pnfs_layout_hdr *layoutid,
 893                       struct nfs4_layoutget_res *lgr,
 894                       gfp_t gfp_flags)
 895 {
 896         struct nfs4_filelayout_segment *fl;
 897         int rc;
 898         struct nfs4_deviceid id;
 899
 900         dprintk("--> %s\n", __func__);
 901         fl = kzalloc(sizeof(*fl), gfp_flags);
 902         if (!fl)
 903                 return NULL;
 904
 905         rc = filelayout_decode_layout(layoutid, fl, lgr, &id, gfp_flags);
 906         if (rc != 0 || filelayout_check_layout(layoutid, fl, lgr, &id, gfp_flags)) {
 907                 _filelayout_free_lseg(fl);
 908                 return NULL;
 909         }
 910         return &fl->generic_hdr;
 911 }
 912
 913 /*
 914  * filelayout_pg_test(). Called by nfs_can_coalesce_requests()
 915  *
 916  * return true  : coalesce page
 917  * return false : don't coalesce page
 918  */
 919 static bool
 920 filelayout_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
 921                    struct nfs_page *req)
 922 {
 923         u64 p_stripe, r_stripe;
 924         u32 stripe_unit;
 925
 926         if (!pnfs_generic_pg_test(pgio, prev, req) ||
 927             !nfs_generic_pg_test(pgio, prev, req))
 928                 return false;
 929
 930         p_stripe = (u64)req_offset(prev);
 931         r_stripe = (u64)req_offset(req);
 932         stripe_unit = FILELAYOUT_LSEG(pgio->pg_lseg)->stripe_unit;
 933
 934         do_div(p_stripe, stripe_unit);
 935         do_div(r_stripe, stripe_unit);
 936
 937         return (p_stripe == r_stripe);
 938 }
 939
 940 static void
 941 filelayout_pg_init_read(struct nfs_pageio_descriptor *pgio,
 942                         struct nfs_page *req)
 943 {
 944         WARN_ON_ONCE(pgio->pg_lseg != NULL);
 945
 946         if (req->wb_offset != req->wb_pgbase) {
 947                 /*
 948                  * Handling unaligned pages is difficult, because have to
 949                  * somehow split a req in two in certain cases in the
 950                  * pg.test code.  Avoid this by just not using pnfs
 951                  * in this case.
 952                  */
 953                 nfs_pageio_reset_read_mds(pgio);
 954                 return;
 955         }
 956         pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
 957                                            req->wb_context,
 958                                            0,
 959                                            NFS4_MAX_UINT64,
 960                                            IOMODE_READ,
 961                                            GFP_KERNEL);
 962         /* If no lseg, fall back to read through mds */
 963         if (pgio->pg_lseg == NULL)
 964                 nfs_pageio_reset_read_mds(pgio);
 965 }
 966
 967 static void
 968 filelayout_pg_init_write(struct nfs_pageio_descriptor *pgio,
 969                          struct nfs_page *req)
 970 {
 971         struct nfs_commit_info cinfo;
 972         int status;
 973
 974         WARN_ON_ONCE(pgio->pg_lseg != NULL);
 975
 976         if (req->wb_offset != req->wb_pgbase)
 977                 goto out_mds;
 978         pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
 979                                            req->wb_context,
 980                                            0,
 981                                            NFS4_MAX_UINT64,
 982                                            IOMODE_RW,
 983                                            GFP_NOFS);
 984         /* If no lseg, fall back to write through mds */
 985         if (pgio->pg_lseg == NULL)
 986                 goto out_mds;
 987         nfs_init_cinfo(&cinfo, pgio->pg_inode, pgio->pg_dreq);
 988         status = filelayout_alloc_commit_info(pgio->pg_lseg, &cinfo, GFP_NOFS);
 989         if (status < 0) {
 990                 pnfs_put_lseg(pgio->pg_lseg);
 991                 pgio->pg_lseg = NULL;
 992                 goto out_mds;
 993         }
 994         return;
 995 out_mds:
 996         nfs_pageio_reset_write_mds(pgio);
 997 }
 998
 999 static const struct nfs_pageio_ops filelayout_pg_read_ops = {
1000         .pg_init = filelayout_pg_init_read,
1001         .pg_test = filelayout_pg_test,
1002         .pg_doio = pnfs_generic_pg_readpages,
1003 };
1004
1005 static const struct nfs_pageio_ops filelayout_pg_write_ops = {
1006         .pg_init = filelayout_pg_init_write,
1007         .pg_test = filelayout_pg_test,
1008         .pg_doio = pnfs_generic_pg_writepages,
1009 };
1010
1011 static u32 select_bucket_index(struct nfs4_filelayout_segment *fl, u32 j)
1012 {
1013         if (fl->stripe_type == STRIPE_SPARSE)
1014                 return nfs4_fl_calc_ds_index(&fl->generic_hdr, j);
1015         else
1016                 return j;
1017 }
1018
1019 /* The generic layer is about to remove the req from the commit list.
1020  * If this will make the bucket empty, it will need to put the lseg reference.
1021  */
1022 static void
1023 filelayout_clear_request_commit(struct nfs_page *req,
1024                                 struct nfs_commit_info *cinfo)
1025 {
1026         struct pnfs_layout_segment *freeme = NULL;
1027
1028         spin_lock(cinfo->lock);
1029         if (!test_and_clear_bit(PG_COMMIT_TO_DS, &req->wb_flags))
1030                 goto out;
1031         cinfo->ds->nwritten--;
1032         if (list_is_singular(&req->wb_list)) {
1033                 struct pnfs_commit_bucket *bucket;
1034
1035                 bucket = list_first_entry(&req->wb_list,
1036                                           struct pnfs_commit_bucket,
1037                                           written);
1038                 freeme = bucket->wlseg;
1039                 bucket->wlseg = NULL;
1040         }
1041 out:
1042         nfs_request_remove_commit_list(req, cinfo);
1043         spin_unlock(cinfo->lock);
1044         pnfs_put_lseg(freeme);
1045 }
1046
1047 static struct list_head *
1048 filelayout_choose_commit_list(struct nfs_page *req,
1049                               struct pnfs_layout_segment *lseg,
1050                               struct nfs_commit_info *cinfo)
1051 {
1052         struct nfs4_filelayout_segment *fl = FILELAYOUT_LSEG(lseg);
1053         u32 i, j;
1054         struct list_head *list;
1055         struct pnfs_commit_bucket *buckets;
1056
1057         if (fl->commit_through_mds)
1058                 return &cinfo->mds->list;
1059
1060         /* Note that we are calling nfs4_fl_calc_j_index on each page
1061          * that ends up being committed to a data server.  An attractive
1062          * alternative is to add a field to nfs_write_data and nfs_page
1063          * to store the value calculated in filelayout_write_pagelist
1064          * and just use that here.
1065          */
1066         j = nfs4_fl_calc_j_index(lseg, req_offset(req));
1067         i = select_bucket_index(fl, j);
1068         buckets = cinfo->ds->buckets;
1069         list = &buckets[i].written;
1070         if (list_empty(list)) {
1071                 /* Non-empty buckets hold a reference on the lseg.  That ref
1072                  * is normally transferred to the COMMIT call and released
1073                  * there.  It could also be released if the last req is pulled
1074                  * off due to a rewrite, in which case it will be done in
1075                  * filelayout_clear_request_commit
1076                  */
1077                 buckets[i].wlseg = pnfs_get_lseg(lseg);
1078         }
1079         set_bit(PG_COMMIT_TO_DS, &req->wb_flags);
1080         cinfo->ds->nwritten++;
1081         return list;
1082 }
1083
1084 static void
1085 filelayout_mark_request_commit(struct nfs_page *req,
1086                                struct pnfs_layout_segment *lseg,
1087                                struct nfs_commit_info *cinfo)
1088 {
1089         struct list_head *list;
1090
1091         list = filelayout_choose_commit_list(req, lseg, cinfo);
1092         nfs_request_add_commit_list(req, list, cinfo);
1093 }
1094
1095 static u32 calc_ds_index_from_commit(struct pnfs_layout_segment *lseg, u32 i)
1096 {
1097         struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
1098
1099         if (flseg->stripe_type == STRIPE_SPARSE)
1100                 return i;
1101         else
1102                 return nfs4_fl_calc_ds_index(lseg, i);
1103 }
1104
1105 static struct nfs_fh *
1106 select_ds_fh_from_commit(struct pnfs_layout_segment *lseg, u32 i)
1107 {
1108         struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
1109
1110         if (flseg->stripe_type == STRIPE_SPARSE) {
1111                 if (flseg->num_fh == 1)
1112                         i = 0;
1113                 else if (flseg->num_fh == 0)
1114                         /* Use the MDS OPEN fh set in nfs_read_rpcsetup */
1115                         return NULL;
1116         }
1117         return flseg->fh_array[i];
1118 }
1119
1120 static int filelayout_initiate_commit(struct nfs_commit_data *data, int how)
1121 {
1122         struct pnfs_layout_segment *lseg = data->lseg;
1123         struct nfs4_pnfs_ds *ds;
1124         struct rpc_clnt *ds_clnt;
1125         u32 idx;
1126         struct nfs_fh *fh;
1127
1128         idx = calc_ds_index_from_commit(lseg, data->ds_commit_index);
1129         ds = nfs4_fl_prepare_ds(lseg, idx);
1130         if (!ds)
1131                 goto out_err;
1132
1133         ds_clnt = nfs4_find_or_create_ds_client(ds->ds_clp, data->inode);
1134         if (IS_ERR(ds_clnt))
1135                 goto out_err;
1136
1137         dprintk("%s ino %lu, how %d cl_count %d\n", __func__,
1138                 data->inode->i_ino, how, atomic_read(&ds->ds_clp->cl_count));
1139         data->commit_done_cb = filelayout_commit_done_cb;
1140         atomic_inc(&ds->ds_clp->cl_count);
1141         data->ds_clp = ds->ds_clp;
1142         fh = select_ds_fh_from_commit(lseg, data->ds_commit_index);
1143         if (fh)
1144                 data->args.fh = fh;
1145         return nfs_initiate_commit(ds_clnt, data,
1146                                    &filelayout_commit_call_ops, how,
1147                                    RPC_TASK_SOFTCONN);
1148 out_err:
1149         prepare_to_resend_writes(data);
1150         filelayout_commit_release(data);
1151         return -EAGAIN;
1152 }
1153
1154 static int
1155 transfer_commit_list(struct list_head *src, struct list_head *dst,
1156                      struct nfs_commit_info *cinfo, int max)
1157 {
1158         struct nfs_page *req, *tmp;
1159         int ret = 0;
1160
1161         list_for_each_entry_safe(req, tmp, src, wb_list) {
1162                 if (!nfs_lock_request(req))
1163                         continue;
1164                 kref_get(&req->wb_kref);
1165                 if (cond_resched_lock(cinfo->lock))
1166                         list_safe_reset_next(req, tmp, wb_list);
1167                 nfs_request_remove_commit_list(req, cinfo);
1168                 clear_bit(PG_COMMIT_TO_DS, &req->wb_flags);
1169                 nfs_list_add_request(req, dst);
1170                 ret++;
1171                 if ((ret == max) && !cinfo->dreq)
1172                         break;
1173         }
1174         return ret;
1175 }
1176
1177 static int
1178 filelayout_scan_ds_commit_list(struct pnfs_commit_bucket *bucket,
1179                                struct nfs_commit_info *cinfo,
1180                                int max)
1181 {
1182         struct list_head *src = &bucket->written;
1183         struct list_head *dst = &bucket->committing;
1184         int ret;
1185
1186         ret = transfer_commit_list(src, dst, cinfo, max);
1187         if (ret) {
1188                 cinfo->ds->nwritten -= ret;
1189                 cinfo->ds->ncommitting += ret;
1190                 bucket->clseg = bucket->wlseg;
1191                 if (list_empty(src))
1192                         bucket->wlseg = NULL;
1193                 else
1194                         pnfs_get_lseg(bucket->clseg);
1195         }
1196         return ret;
1197 }
1198
1199 /* Move reqs from written to committing lists, returning count of number moved.
1200  * Note called with cinfo->lock held.
1201  */
1202 static int filelayout_scan_commit_lists(struct nfs_commit_info *cinfo,
1203                                         int max)
1204 {
1205         int i, rv = 0, cnt;
1206
1207         for (i = 0; i < cinfo->ds->nbuckets && max != 0; i++) {
1208                 cnt = filelayout_scan_ds_commit_list(&cinfo->ds->buckets[i],
1209                                                      cinfo, max);
1210                 max -= cnt;
1211                 rv += cnt;
1212         }
1213         return rv;
1214 }
1215
1216 /* Pull everything off the committing lists and dump into @dst */
1217 static void filelayout_recover_commit_reqs(struct list_head *dst,
1218                                            struct nfs_commit_info *cinfo)
1219 {
1220         struct pnfs_commit_bucket *b;
1221         int i;
1222
1223         spin_lock(cinfo->lock);
1224         for (i = 0, b = cinfo->ds->buckets; i < cinfo->ds->nbuckets; i++, b++) {
1225                 if (transfer_commit_list(&b->written, dst, cinfo, 0)) {
1226                         spin_unlock(cinfo->lock);
1227                         pnfs_put_lseg(b->wlseg);
1228                         b->wlseg = NULL;
1229                         spin_lock(cinfo->lock);
1230                 }
1231         }
1232         cinfo->ds->nwritten = 0;
1233         spin_unlock(cinfo->lock);
1234 }
1235
1236 static unsigned int
1237 alloc_ds_commits(struct nfs_commit_info *cinfo, struct list_head *list)
1238 {
1239         struct pnfs_ds_commit_info *fl_cinfo;
1240         struct pnfs_commit_bucket *bucket;
1241         struct nfs_commit_data *data;
1242         int i, j;
1243         unsigned int nreq = 0;
1244
1245         fl_cinfo = cinfo->ds;
1246         bucket = fl_cinfo->buckets;
1247         for (i = 0; i < fl_cinfo->nbuckets; i++, bucket++) {
1248                 if (list_empty(&bucket->committing))
1249                         continue;
1250                 data = nfs_commitdata_alloc();
1251                 if (!data)
1252                         break;
1253                 data->ds_commit_index = i;
1254                 data->lseg = bucket->clseg;
1255                 bucket->clseg = NULL;
1256                 list_add(&data->pages, list);
1257                 nreq++;
1258         }
1259
1260         /* Clean up on error */
1261         for (j = i; j < fl_cinfo->nbuckets; j++, bucket++) {
1262                 if (list_empty(&bucket->committing))
1263                         continue;
1264                 nfs_retry_commit(&bucket->committing, bucket->clseg, cinfo);
1265                 pnfs_put_lseg(bucket->clseg);
1266                 bucket->clseg = NULL;
1267         }
1268         /* Caller will clean up entries put on list */
1269         return nreq;
1270 }
1271
1272 /* This follows nfs_commit_list pretty closely */
1273 static int
1274 filelayout_commit_pagelist(struct inode *inode, struct list_head *mds_pages,
1275                            int how, struct nfs_commit_info *cinfo)
1276 {
1277         struct nfs_commit_data *data, *tmp;
1278         LIST_HEAD(list);
1279         unsigned int nreq = 0;
1280
1281         if (!list_empty(mds_pages)) {
1282                 data = nfs_commitdata_alloc();
1283                 if (data != NULL) {
1284                         data->lseg = NULL;
1285                         list_add(&data->pages, &list);
1286                         nreq++;
1287                 } else
1288                         nfs_retry_commit(mds_pages, NULL, cinfo);
1289         }
1290
1291         nreq += alloc_ds_commits(cinfo, &list);
1292
1293         if (nreq == 0) {
1294                 cinfo->completion_ops->error_cleanup(NFS_I(inode));
1295                 goto out;
1296         }
1297
1298         atomic_add(nreq, &cinfo->mds->rpcs_out);
1299
1300         list_for_each_entry_safe(data, tmp, &list, pages) {
1301                 list_del_init(&data->pages);
1302                 if (!data->lseg) {
1303                         nfs_init_commit(data, mds_pages, NULL, cinfo);
1304                         nfs_initiate_commit(NFS_CLIENT(inode), data,
1305                                             data->mds_ops, how, 0);
1306                 } else {
1307                         struct pnfs_commit_bucket *buckets;
1308
1309                         buckets = cinfo->ds->buckets;
1310                         nfs_init_commit(data, &buckets[data->ds_commit_index].committing, data->lseg, cinfo);
1311                         filelayout_initiate_commit(data, how);
1312                 }
1313         }
1314 out:
1315         cinfo->ds->ncommitting = 0;
1316         return PNFS_ATTEMPTED;
1317 }
1318
1319 static void
1320 filelayout_free_deveiceid_node(struct nfs4_deviceid_node *d)
1321 {
1322         nfs4_fl_free_deviceid(container_of(d, struct nfs4_file_layout_dsaddr, id_node));
1323 }
1324
1325 static struct pnfs_layout_hdr *
1326 filelayout_alloc_layout_hdr(struct inode *inode, gfp_t gfp_flags)
1327 {
1328         struct nfs4_filelayout *flo;
1329
1330         flo = kzalloc(sizeof(*flo), gfp_flags);
1331         return &flo->generic_hdr;
1332 }
1333
1334 static void
1335 filelayout_free_layout_hdr(struct pnfs_layout_hdr *lo)
1336 {
1337         kfree(FILELAYOUT_FROM_HDR(lo));
1338 }
1339
1340 static struct pnfs_ds_commit_info *
1341 filelayout_get_ds_info(struct inode *inode)
1342 {
1343         struct pnfs_layout_hdr *layout = NFS_I(inode)->layout;
1344
1345         if (layout == NULL)
1346                 return NULL;
1347         else
1348                 return &FILELAYOUT_FROM_HDR(layout)->commit_info;
1349 }
1350
1351 static struct pnfs_layoutdriver_type filelayout_type = {
1352         .id                     = LAYOUT_NFSV4_1_FILES,
1353         .name                   = "LAYOUT_NFSV4_1_FILES",
1354         .owner                  = THIS_MODULE,
1355         .alloc_layout_hdr       = filelayout_alloc_layout_hdr,
1356         .free_layout_hdr        = filelayout_free_layout_hdr,
1357         .alloc_lseg             = filelayout_alloc_lseg,
1358         .free_lseg              = filelayout_free_lseg,
1359         .pg_read_ops            = &filelayout_pg_read_ops,
1360         .pg_write_ops           = &filelayout_pg_write_ops,
1361         .get_ds_info            = &filelayout_get_ds_info,
1362         .mark_request_commit    = filelayout_mark_request_commit,
1363         .clear_request_commit   = filelayout_clear_request_commit,
1364         .scan_commit_lists      = filelayout_scan_commit_lists,
1365         .recover_commit_reqs    = filelayout_recover_commit_reqs,
1366         .commit_pagelist        = filelayout_commit_pagelist,
1367         .read_pagelist          = filelayout_read_pagelist,
1368         .write_pagelist         = filelayout_write_pagelist,
1369         .free_deviceid_node     = filelayout_free_deveiceid_node,
1370 };
1371
1372 static int __init nfs4filelayout_init(void)
1373 {
1374         printk(KERN_INFO "%s: NFSv4 File Layout Driver Registering...\n",
1375                __func__);
1376         return pnfs_register_layoutdriver(&filelayout_type);
1377 }
1378
1379 static void __exit nfs4filelayout_exit(void)
1380 {
1381         printk(KERN_INFO "%s: NFSv4 File Layout Driver Unregistering...\n",
1382                __func__);
1383         pnfs_unregister_layoutdriver(&filelayout_type);
1384 }
1385
1386 MODULE_ALIAS("nfs-layouttype4-1");
1387
1388 module_init(nfs4filelayout_init);
1389 module_exit(nfs4filelayout_exit);