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 void filelayout_fenceme(struct inode *inode, struct pnfs_layout_hdr *lo)
 122 {
 123         if (!test_and_clear_bit(NFS_LAYOUT_RETURN, &lo->plh_flags))
 124                 return;
 125         pnfs_return_layout(inode);
 126 }
 127
 128 static int filelayout_async_handle_error(struct rpc_task *task,
 129                                          struct nfs4_state *state,
 130                                          struct nfs_client *clp,
 131                                          struct pnfs_layout_segment *lseg)
 132 {
 133         struct pnfs_layout_hdr *lo = lseg->pls_layout;
 134         struct inode *inode = lo->plh_inode;
 135         struct nfs_server *mds_server = NFS_SERVER(inode);
 136         struct nfs4_deviceid_node *devid = FILELAYOUT_DEVID_NODE(lseg);
 137         struct nfs_client *mds_client = mds_server->nfs_client;
 138         struct nfs4_slot_table *tbl = &clp->cl_session->fc_slot_table;
 139
 140         if (task->tk_status >= 0)
 141                 return 0;
 142
 143         switch (task->tk_status) {
 144         /* MDS state errors */
 145         case -NFS4ERR_DELEG_REVOKED:
 146         case -NFS4ERR_ADMIN_REVOKED:
 147         case -NFS4ERR_BAD_STATEID:
 148                 if (state == NULL)
 149                         break;
 150                 nfs_remove_bad_delegation(state->inode);
 151         case -NFS4ERR_OPENMODE:
 152                 if (state == NULL)
 153                         break;
 154                 if (nfs4_schedule_stateid_recovery(mds_server, state) < 0)
 155                         goto out_bad_stateid;
 156                 goto wait_on_recovery;
 157         case -NFS4ERR_EXPIRED:
 158                 if (state != NULL) {
 159                         if (nfs4_schedule_stateid_recovery(mds_server, state) < 0)
 160                                 goto out_bad_stateid;
 161                 }
 162                 nfs4_schedule_lease_recovery(mds_client);
 163                 goto wait_on_recovery;
 164         /* DS session errors */
 165         case -NFS4ERR_BADSESSION:
 166         case -NFS4ERR_BADSLOT:
 167         case -NFS4ERR_BAD_HIGH_SLOT:
 168         case -NFS4ERR_DEADSESSION:
 169         case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
 170         case -NFS4ERR_SEQ_FALSE_RETRY:
 171         case -NFS4ERR_SEQ_MISORDERED:
 172                 dprintk("%s ERROR %d, Reset session. Exchangeid "
 173                         "flags 0x%x\n", __func__, task->tk_status,
 174                         clp->cl_exchange_flags);
 175                 nfs4_schedule_session_recovery(clp->cl_session, task->tk_status);
 176                 break;
 177         case -NFS4ERR_DELAY:
 178         case -NFS4ERR_GRACE:
 179                 rpc_delay(task, FILELAYOUT_POLL_RETRY_MAX);
 180                 break;
 181         case -NFS4ERR_RETRY_UNCACHED_REP:
 182                 break;
 183         /* Invalidate Layout errors */
 184         case -NFS4ERR_PNFS_NO_LAYOUT:
 185         case -ESTALE:           /* mapped NFS4ERR_STALE */
 186         case -EBADHANDLE:       /* mapped NFS4ERR_BADHANDLE */
 187         case -EISDIR:           /* mapped NFS4ERR_ISDIR */
 188         case -NFS4ERR_FHEXPIRED:
 189         case -NFS4ERR_WRONG_TYPE:
 190                 dprintk("%s Invalid layout error %d\n", __func__,
 191                         task->tk_status);
 192                 /*
 193                  * Destroy layout so new i/o will get a new layout.
 194                  * Layout will not be destroyed until all current lseg
 195                  * references are put. Mark layout as invalid to resend failed
 196                  * i/o and all i/o waiting on the slot table to the MDS until
 197                  * layout is destroyed and a new valid layout is obtained.
 198                  */
 199                 pnfs_destroy_layout(NFS_I(inode));
 200                 rpc_wake_up(&tbl->slot_tbl_waitq);
 201                 goto reset;
 202         /* RPC connection errors */
 203         case -ECONNREFUSED:
 204         case -EHOSTDOWN:
 205         case -EHOSTUNREACH:
 206         case -ENETUNREACH:
 207         case -EIO:
 208         case -ETIMEDOUT:
 209         case -EPIPE:
 210                 dprintk("%s DS connection error %d\n", __func__,
 211                         task->tk_status);
 212                 nfs4_mark_deviceid_unavailable(devid);
 213                 set_bit(NFS_LAYOUT_RETURN, &lo->plh_flags);
 214                 rpc_wake_up(&tbl->slot_tbl_waitq);
 215                 /* fall through */
 216         default:
 217 reset:
 218                 dprintk("%s Retry through MDS. Error %d\n", __func__,
 219                         task->tk_status);
 220                 return -NFS4ERR_RESET_TO_MDS;
 221         }
 222 out:
 223         task->tk_status = 0;
 224         return -EAGAIN;
 225 out_bad_stateid:
 226         task->tk_status = -EIO;
 227         return 0;
 228 wait_on_recovery:
 229         rpc_sleep_on(&mds_client->cl_rpcwaitq, task, NULL);
 230         if (test_bit(NFS4CLNT_MANAGER_RUNNING, &mds_client->cl_state) == 0)
 231                 rpc_wake_up_queued_task(&mds_client->cl_rpcwaitq, task);
 232         goto out;
 233 }
 234
 235 /* NFS_PROTO call done callback routines */
 236
 237 static int filelayout_read_done_cb(struct rpc_task *task,
 238                                 struct nfs_pgio_header *hdr)
 239 {
 240         int err;
 241
 242         trace_nfs4_pnfs_read(hdr, task->tk_status);
 243         err = filelayout_async_handle_error(task, hdr->args.context->state,
 244                                             hdr->ds_clp, hdr->lseg);
 245
 246         switch (err) {
 247         case -NFS4ERR_RESET_TO_MDS:
 248                 filelayout_reset_read(hdr);
 249                 return task->tk_status;
 250         case -EAGAIN:
 251                 rpc_restart_call_prepare(task);
 252                 return -EAGAIN;
 253         }
 254
 255         return 0;
 256 }
 257
 258 /*
 259  * We reference the rpc_cred of the first WRITE that triggers the need for
 260  * a LAYOUTCOMMIT, and use it to send the layoutcommit compound.
 261  * rfc5661 is not clear about which credential should be used.
 262  */
 263 static void
 264 filelayout_set_layoutcommit(struct nfs_pgio_header *hdr)
 265 {
 266
 267         if (FILELAYOUT_LSEG(hdr->lseg)->commit_through_mds ||
 268             hdr->res.verf->committed != NFS_DATA_SYNC)
 269                 return;
 270
 271         pnfs_set_layoutcommit(hdr);
 272         dprintk("%s inode %lu pls_end_pos %lu\n", __func__, hdr->inode->i_ino,
 273                 (unsigned long) NFS_I(hdr->inode)->layout->plh_lwb);
 274 }
 275
 276 bool
 277 filelayout_test_devid_unavailable(struct nfs4_deviceid_node *node)
 278 {
 279         return filelayout_test_devid_invalid(node) ||
 280                 nfs4_test_deviceid_unavailable(node);
 281 }
 282
 283 static bool
 284 filelayout_reset_to_mds(struct pnfs_layout_segment *lseg)
 285 {
 286         struct nfs4_deviceid_node *node = FILELAYOUT_DEVID_NODE(lseg);
 287
 288         return filelayout_test_devid_unavailable(node);
 289 }
 290
 291 /*
 292  * Call ops for the async read/write cases
 293  * In the case of dense layouts, the offset needs to be reset to its
 294  * original value.
 295  */
 296 static void filelayout_read_prepare(struct rpc_task *task, void *data)
 297 {
 298         struct nfs_pgio_header *hdr = data;
 299
 300         if (unlikely(test_bit(NFS_CONTEXT_BAD, &hdr->args.context->flags))) {
 301                 rpc_exit(task, -EIO);
 302                 return;
 303         }
 304         if (filelayout_reset_to_mds(hdr->lseg)) {
 305                 dprintk("%s task %u reset io to MDS\n", __func__, task->tk_pid);
 306                 filelayout_reset_read(hdr);
 307                 rpc_exit(task, 0);
 308                 return;
 309         }
 310         hdr->pgio_done_cb = filelayout_read_done_cb;
 311
 312         if (nfs41_setup_sequence(hdr->ds_clp->cl_session,
 313                         &hdr->args.seq_args,
 314                         &hdr->res.seq_res,
 315                         task))
 316                 return;
 317         if (nfs4_set_rw_stateid(&hdr->args.stateid, hdr->args.context,
 318                         hdr->args.lock_context, FMODE_READ) == -EIO)
 319                 rpc_exit(task, -EIO); /* lost lock, terminate I/O */
 320 }
 321
 322 static void filelayout_read_call_done(struct rpc_task *task, void *data)
 323 {
 324         struct nfs_pgio_header *hdr = data;
 325
 326         dprintk("--> %s task->tk_status %d\n", __func__, task->tk_status);
 327
 328         if (test_bit(NFS_IOHDR_REDO, &hdr->flags) &&
 329             task->tk_status == 0) {
 330                 nfs41_sequence_done(task, &hdr->res.seq_res);
 331                 return;
 332         }
 333
 334         /* Note this may cause RPC to be resent */
 335         hdr->mds_ops->rpc_call_done(task, data);
 336 }
 337
 338 static void filelayout_read_count_stats(struct rpc_task *task, void *data)
 339 {
 340         struct nfs_pgio_header *hdr = data;
 341
 342         rpc_count_iostats(task, NFS_SERVER(hdr->inode)->client->cl_metrics);
 343 }
 344
 345 static void filelayout_read_release(void *data)
 346 {
 347         struct nfs_pgio_header *hdr = data;
 348         struct pnfs_layout_hdr *lo = hdr->lseg->pls_layout;
 349
 350         filelayout_fenceme(lo->plh_inode, lo);
 351         nfs_put_client(hdr->ds_clp);
 352         hdr->mds_ops->rpc_release(data);
 353 }
 354
 355 static int filelayout_write_done_cb(struct rpc_task *task,
 356                                 struct nfs_pgio_header *hdr)
 357 {
 358         int err;
 359
 360         trace_nfs4_pnfs_write(hdr, task->tk_status);
 361         err = filelayout_async_handle_error(task, hdr->args.context->state,
 362                                             hdr->ds_clp, hdr->lseg);
 363
 364         switch (err) {
 365         case -NFS4ERR_RESET_TO_MDS:
 366                 filelayout_reset_write(hdr);
 367                 return task->tk_status;
 368         case -EAGAIN:
 369                 rpc_restart_call_prepare(task);
 370                 return -EAGAIN;
 371         }
 372
 373         filelayout_set_layoutcommit(hdr);
 374         return 0;
 375 }
 376
 377 /* Fake up some data that will cause nfs_commit_release to retry the writes. */
 378 static void prepare_to_resend_writes(struct nfs_commit_data *data)
 379 {
 380         struct nfs_page *first = nfs_list_entry(data->pages.next);
 381
 382         data->task.tk_status = 0;
 383         memcpy(&data->verf.verifier, &first->wb_verf,
 384                sizeof(data->verf.verifier));
 385         data->verf.verifier.data[0]++; /* ensure verifier mismatch */
 386 }
 387
 388 static int filelayout_commit_done_cb(struct rpc_task *task,
 389                                      struct nfs_commit_data *data)
 390 {
 391         int err;
 392
 393         trace_nfs4_pnfs_commit_ds(data, task->tk_status);
 394         err = filelayout_async_handle_error(task, NULL, data->ds_clp,
 395                                             data->lseg);
 396
 397         switch (err) {
 398         case -NFS4ERR_RESET_TO_MDS:
 399                 prepare_to_resend_writes(data);
 400                 return -EAGAIN;
 401         case -EAGAIN:
 402                 rpc_restart_call_prepare(task);
 403                 return -EAGAIN;
 404         }
 405
 406         if (data->verf.committed == NFS_UNSTABLE)
 407                 pnfs_commit_set_layoutcommit(data);
 408
 409         return 0;
 410 }
 411
 412 static void filelayout_write_prepare(struct rpc_task *task, void *data)
 413 {
 414         struct nfs_pgio_header *hdr = data;
 415
 416         if (unlikely(test_bit(NFS_CONTEXT_BAD, &hdr->args.context->flags))) {
 417                 rpc_exit(task, -EIO);
 418                 return;
 419         }
 420         if (filelayout_reset_to_mds(hdr->lseg)) {
 421                 dprintk("%s task %u reset io to MDS\n", __func__, task->tk_pid);
 422                 filelayout_reset_write(hdr);
 423                 rpc_exit(task, 0);
 424                 return;
 425         }
 426         if (nfs41_setup_sequence(hdr->ds_clp->cl_session,
 427                         &hdr->args.seq_args,
 428                         &hdr->res.seq_res,
 429                         task))
 430                 return;
 431         if (nfs4_set_rw_stateid(&hdr->args.stateid, hdr->args.context,
 432                         hdr->args.lock_context, FMODE_WRITE) == -EIO)
 433                 rpc_exit(task, -EIO); /* lost lock, terminate I/O */
 434 }
 435
 436 static void filelayout_write_call_done(struct rpc_task *task, void *data)
 437 {
 438         struct nfs_pgio_header *hdr = data;
 439
 440         if (test_bit(NFS_IOHDR_REDO, &hdr->flags) &&
 441             task->tk_status == 0) {
 442                 nfs41_sequence_done(task, &hdr->res.seq_res);
 443                 return;
 444         }
 445
 446         /* Note this may cause RPC to be resent */
 447         hdr->mds_ops->rpc_call_done(task, data);
 448 }
 449
 450 static void filelayout_write_count_stats(struct rpc_task *task, void *data)
 451 {
 452         struct nfs_pgio_header *hdr = data;
 453
 454         rpc_count_iostats(task, NFS_SERVER(hdr->inode)->client->cl_metrics);
 455 }
 456
 457 static void filelayout_write_release(void *data)
 458 {
 459         struct nfs_pgio_header *hdr = data;
 460         struct pnfs_layout_hdr *lo = hdr->lseg->pls_layout;
 461
 462         filelayout_fenceme(lo->plh_inode, lo);
 463         nfs_put_client(hdr->ds_clp);
 464         hdr->mds_ops->rpc_release(data);
 465 }
 466
 467 static void filelayout_commit_prepare(struct rpc_task *task, void *data)
 468 {
 469         struct nfs_commit_data *wdata = data;
 470
 471         nfs41_setup_sequence(wdata->ds_clp->cl_session,
 472                         &wdata->args.seq_args,
 473                         &wdata->res.seq_res,
 474                         task);
 475 }
 476
 477 static void filelayout_write_commit_done(struct rpc_task *task, void *data)
 478 {
 479         struct nfs_commit_data *wdata = data;
 480
 481         /* Note this may cause RPC to be resent */
 482         wdata->mds_ops->rpc_call_done(task, data);
 483 }
 484
 485 static void filelayout_commit_count_stats(struct rpc_task *task, void *data)
 486 {
 487         struct nfs_commit_data *cdata = data;
 488
 489         rpc_count_iostats(task, NFS_SERVER(cdata->inode)->client->cl_metrics);
 490 }
 491
 492 static void filelayout_commit_release(void *calldata)
 493 {
 494         struct nfs_commit_data *data = calldata;
 495
 496         data->completion_ops->completion(data);
 497         pnfs_put_lseg(data->lseg);
 498         nfs_put_client(data->ds_clp);
 499         nfs_commitdata_release(data);
 500 }
 501
 502 static const struct rpc_call_ops filelayout_read_call_ops = {
 503         .rpc_call_prepare = filelayout_read_prepare,
 504         .rpc_call_done = filelayout_read_call_done,
 505         .rpc_count_stats = filelayout_read_count_stats,
 506         .rpc_release = filelayout_read_release,
 507 };
 508
 509 static const struct rpc_call_ops filelayout_write_call_ops = {
 510         .rpc_call_prepare = filelayout_write_prepare,
 511         .rpc_call_done = filelayout_write_call_done,
 512         .rpc_count_stats = filelayout_write_count_stats,
 513         .rpc_release = filelayout_write_release,
 514 };
 515
 516 static const struct rpc_call_ops filelayout_commit_call_ops = {
 517         .rpc_call_prepare = filelayout_commit_prepare,
 518         .rpc_call_done = filelayout_write_commit_done,
 519         .rpc_count_stats = filelayout_commit_count_stats,
 520         .rpc_release = filelayout_commit_release,
 521 };
 522
 523 static enum pnfs_try_status
 524 filelayout_read_pagelist(struct nfs_pgio_header *hdr)
 525 {
 526         struct pnfs_layout_segment *lseg = hdr->lseg;
 527         struct nfs4_pnfs_ds *ds;
 528         struct rpc_clnt *ds_clnt;
 529         loff_t offset = hdr->args.offset;
 530         u32 j, idx;
 531         struct nfs_fh *fh;
 532
 533         dprintk("--> %s ino %lu pgbase %u req %Zu@%llu\n",
 534                 __func__, hdr->inode->i_ino,
 535                 hdr->args.pgbase, (size_t)hdr->args.count, offset);
 536
 537         /* Retrieve the correct rpc_client for the byte range */
 538         j = nfs4_fl_calc_j_index(lseg, offset);
 539         idx = nfs4_fl_calc_ds_index(lseg, j);
 540         ds = nfs4_fl_prepare_ds(lseg, idx);
 541         if (!ds)
 542                 return PNFS_NOT_ATTEMPTED;
 543
 544         ds_clnt = nfs4_find_or_create_ds_client(ds->ds_clp, hdr->inode);
 545         if (IS_ERR(ds_clnt))
 546                 return PNFS_NOT_ATTEMPTED;
 547
 548         dprintk("%s USE DS: %s cl_count %d\n", __func__,
 549                 ds->ds_remotestr, atomic_read(&ds->ds_clp->cl_count));
 550
 551         /* No multipath support. Use first DS */
 552         atomic_inc(&ds->ds_clp->cl_count);
 553         hdr->ds_clp = ds->ds_clp;
 554         hdr->ds_idx = idx;
 555         fh = nfs4_fl_select_ds_fh(lseg, j);
 556         if (fh)
 557                 hdr->args.fh = fh;
 558
 559         hdr->args.offset = filelayout_get_dserver_offset(lseg, offset);
 560         hdr->mds_offset = offset;
 561
 562         /* Perform an asynchronous read to ds */
 563         nfs_initiate_pgio(ds_clnt, hdr,
 564                             &filelayout_read_call_ops, 0, RPC_TASK_SOFTCONN);
 565         return PNFS_ATTEMPTED;
 566 }
 567
 568 /* Perform async writes. */
 569 static enum pnfs_try_status
 570 filelayout_write_pagelist(struct nfs_pgio_header *hdr, int sync)
 571 {
 572         struct pnfs_layout_segment *lseg = hdr->lseg;
 573         struct nfs4_pnfs_ds *ds;
 574         struct rpc_clnt *ds_clnt;
 575         loff_t offset = hdr->args.offset;
 576         u32 j, idx;
 577         struct nfs_fh *fh;
 578
 579         /* Retrieve the correct rpc_client for the byte range */
 580         j = nfs4_fl_calc_j_index(lseg, offset);
 581         idx = nfs4_fl_calc_ds_index(lseg, j);
 582         ds = nfs4_fl_prepare_ds(lseg, idx);
 583         if (!ds)
 584                 return PNFS_NOT_ATTEMPTED;
 585
 586         ds_clnt = nfs4_find_or_create_ds_client(ds->ds_clp, hdr->inode);
 587         if (IS_ERR(ds_clnt))
 588                 return PNFS_NOT_ATTEMPTED;
 589
 590         dprintk("%s ino %lu sync %d req %Zu@%llu DS: %s cl_count %d\n",
 591                 __func__, hdr->inode->i_ino, sync, (size_t) hdr->args.count,
 592                 offset, ds->ds_remotestr, atomic_read(&ds->ds_clp->cl_count));
 593
 594         hdr->pgio_done_cb = filelayout_write_done_cb;
 595         atomic_inc(&ds->ds_clp->cl_count);
 596         hdr->ds_clp = ds->ds_clp;
 597         hdr->ds_idx = idx;
 598         fh = nfs4_fl_select_ds_fh(lseg, j);
 599         if (fh)
 600                 hdr->args.fh = fh;
 601         hdr->args.offset = filelayout_get_dserver_offset(lseg, offset);
 602
 603         /* Perform an asynchronous write */
 604         nfs_initiate_pgio(ds_clnt, hdr,
 605                                     &filelayout_write_call_ops, sync,
 606                                     RPC_TASK_SOFTCONN);
 607         return PNFS_ATTEMPTED;
 608 }
 609
 610 /*
 611  * filelayout_check_layout()
 612  *
 613  * Make sure layout segment parameters are sane WRT the device.
 614  * At this point no generic layer initialization of the lseg has occurred,
 615  * and nothing has been added to the layout_hdr cache.
 616  *
 617  */
 618 static int
 619 filelayout_check_layout(struct pnfs_layout_hdr *lo,
 620                         struct nfs4_filelayout_segment *fl,
 621                         struct nfs4_layoutget_res *lgr,
 622                         struct nfs4_deviceid *id,
 623                         gfp_t gfp_flags)
 624 {
 625         struct nfs4_deviceid_node *d;
 626         struct nfs4_file_layout_dsaddr *dsaddr;
 627         int status = -EINVAL;
 628
 629         dprintk("--> %s\n", __func__);
 630
 631         /* FIXME: remove this check when layout segment support is added */
 632         if (lgr->range.offset != 0 ||
 633             lgr->range.length != NFS4_MAX_UINT64) {
 634                 dprintk("%s Only whole file layouts supported. Use MDS i/o\n",
 635                         __func__);
 636                 goto out;
 637         }
 638
 639         if (fl->pattern_offset > lgr->range.offset) {
 640                 dprintk("%s pattern_offset %lld too large\n",
 641                                 __func__, fl->pattern_offset);
 642                 goto out;
 643         }
 644
 645         if (!fl->stripe_unit) {
 646                 dprintk("%s Invalid stripe unit (%u)\n",
 647                         __func__, fl->stripe_unit);
 648                 goto out;
 649         }
 650
 651         /* find and reference the deviceid */
 652         d = nfs4_find_get_deviceid(NFS_SERVER(lo->plh_inode)->pnfs_curr_ld,
 653                                    NFS_SERVER(lo->plh_inode)->nfs_client, id);
 654         if (d == NULL) {
 655                 dsaddr = filelayout_get_device_info(lo->plh_inode, id,
 656                                 lo->plh_lc_cred, gfp_flags);
 657                 if (dsaddr == NULL)
 658                         goto out;
 659         } else
 660                 dsaddr = container_of(d, struct nfs4_file_layout_dsaddr, id_node);
 661         /* Found deviceid is unavailable */
 662         if (filelayout_test_devid_unavailable(&dsaddr->id_node))
 663                         goto out_put;
 664
 665         fl->dsaddr = dsaddr;
 666
 667         if (fl->first_stripe_index >= dsaddr->stripe_count) {
 668                 dprintk("%s Bad first_stripe_index %u\n",
 669                                 __func__, fl->first_stripe_index);
 670                 goto out_put;
 671         }
 672
 673         if ((fl->stripe_type == STRIPE_SPARSE &&
 674             fl->num_fh > 1 && fl->num_fh != dsaddr->ds_num) ||
 675             (fl->stripe_type == STRIPE_DENSE &&
 676             fl->num_fh != dsaddr->stripe_count)) {
 677                 dprintk("%s num_fh %u not valid for given packing\n",
 678                         __func__, fl->num_fh);
 679                 goto out_put;
 680         }
 681
 682         status = 0;
 683 out:
 684         dprintk("--> %s returns %d\n", __func__, status);
 685         return status;
 686 out_put:
 687         nfs4_fl_put_deviceid(dsaddr);
 688         goto out;
 689 }
 690
 691 static void filelayout_free_fh_array(struct nfs4_filelayout_segment *fl)
 692 {
 693         int i;
 694
 695         for (i = 0; i < fl->num_fh; i++) {
 696                 if (!fl->fh_array[i])
 697                         break;
 698                 kfree(fl->fh_array[i]);
 699         }
 700         kfree(fl->fh_array);
 701         fl->fh_array = NULL;
 702 }
 703
 704 static void
 705 _filelayout_free_lseg(struct nfs4_filelayout_segment *fl)
 706 {
 707         filelayout_free_fh_array(fl);
 708         kfree(fl);
 709 }
 710
 711 static int
 712 filelayout_decode_layout(struct pnfs_layout_hdr *flo,
 713                          struct nfs4_filelayout_segment *fl,
 714                          struct nfs4_layoutget_res *lgr,
 715                          struct nfs4_deviceid *id,
 716                          gfp_t gfp_flags)
 717 {
 718         struct xdr_stream stream;
 719         struct xdr_buf buf;
 720         struct page *scratch;
 721         __be32 *p;
 722         uint32_t nfl_util;
 723         int i;
 724
 725         dprintk("%s: set_layout_map Begin\n", __func__);
 726
 727         scratch = alloc_page(gfp_flags);
 728         if (!scratch)
 729                 return -ENOMEM;
 730
 731         xdr_init_decode_pages(&stream, &buf, lgr->layoutp->pages, lgr->layoutp->len);
 732         xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
 733
 734         /* 20 = ufl_util (4), first_stripe_index (4), pattern_offset (8),
 735          * num_fh (4) */
 736         p = xdr_inline_decode(&stream, NFS4_DEVICEID4_SIZE + 20);
 737         if (unlikely(!p))
 738                 goto out_err;
 739
 740         memcpy(id, p, sizeof(*id));
 741         p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);
 742         nfs4_print_deviceid(id);
 743
 744         nfl_util = be32_to_cpup(p++);
 745         if (nfl_util & NFL4_UFLG_COMMIT_THRU_MDS)
 746                 fl->commit_through_mds = 1;
 747         if (nfl_util & NFL4_UFLG_DENSE)
 748                 fl->stripe_type = STRIPE_DENSE;
 749         else
 750                 fl->stripe_type = STRIPE_SPARSE;
 751         fl->stripe_unit = nfl_util & ~NFL4_UFLG_MASK;
 752
 753         fl->first_stripe_index = be32_to_cpup(p++);
 754         p = xdr_decode_hyper(p, &fl->pattern_offset);
 755         fl->num_fh = be32_to_cpup(p++);
 756
 757         dprintk("%s: nfl_util 0x%X num_fh %u fsi %u po %llu\n",
 758                 __func__, nfl_util, fl->num_fh, fl->first_stripe_index,
 759                 fl->pattern_offset);
 760
 761         /* Note that a zero value for num_fh is legal for STRIPE_SPARSE.
 762          * Futher checking is done in filelayout_check_layout */
 763         if (fl->num_fh >
 764             max(NFS4_PNFS_MAX_STRIPE_CNT, NFS4_PNFS_MAX_MULTI_CNT))
 765                 goto out_err;
 766
 767         if (fl->num_fh > 0) {
 768                 fl->fh_array = kcalloc(fl->num_fh, sizeof(fl->fh_array[0]),
 769                                        gfp_flags);
 770                 if (!fl->fh_array)
 771                         goto out_err;
 772         }
 773
 774         for (i = 0; i < fl->num_fh; i++) {
 775                 /* Do we want to use a mempool here? */
 776                 fl->fh_array[i] = kmalloc(sizeof(struct nfs_fh), gfp_flags);
 777                 if (!fl->fh_array[i])
 778                         goto out_err_free;
 779
 780                 p = xdr_inline_decode(&stream, 4);
 781                 if (unlikely(!p))
 782                         goto out_err_free;
 783                 fl->fh_array[i]->size = be32_to_cpup(p++);
 784                 if (sizeof(struct nfs_fh) < fl->fh_array[i]->size) {
 785                         printk(KERN_ERR "NFS: Too big fh %d received %d\n",
 786                                i, fl->fh_array[i]->size);
 787                         goto out_err_free;
 788                 }
 789
 790                 p = xdr_inline_decode(&stream, fl->fh_array[i]->size);
 791                 if (unlikely(!p))
 792                         goto out_err_free;
 793                 memcpy(fl->fh_array[i]->data, p, fl->fh_array[i]->size);
 794                 dprintk("DEBUG: %s: fh len %d\n", __func__,
 795                         fl->fh_array[i]->size);
 796         }
 797
 798         __free_page(scratch);
 799         return 0;
 800
 801 out_err_free:
 802         filelayout_free_fh_array(fl);
 803 out_err:
 804         __free_page(scratch);
 805         return -EIO;
 806 }
 807
 808 static void
 809 filelayout_free_lseg(struct pnfs_layout_segment *lseg)
 810 {
 811         struct nfs4_filelayout_segment *fl = FILELAYOUT_LSEG(lseg);
 812
 813         dprintk("--> %s\n", __func__);
 814         nfs4_fl_put_deviceid(fl->dsaddr);
 815         /* This assumes a single RW lseg */
 816         if (lseg->pls_range.iomode == IOMODE_RW) {
 817                 struct nfs4_filelayout *flo;
 818
 819                 flo = FILELAYOUT_FROM_HDR(lseg->pls_layout);
 820                 flo->commit_info.nbuckets = 0;
 821                 kfree(flo->commit_info.buckets);
 822                 flo->commit_info.buckets = NULL;
 823         }
 824         _filelayout_free_lseg(fl);
 825 }
 826
 827 static int
 828 filelayout_alloc_commit_info(struct pnfs_layout_segment *lseg,
 829                              struct nfs_commit_info *cinfo,
 830                              gfp_t gfp_flags)
 831 {
 832         struct nfs4_filelayout_segment *fl = FILELAYOUT_LSEG(lseg);
 833         struct pnfs_commit_bucket *buckets;
 834         int size, i;
 835
 836         if (fl->commit_through_mds)
 837                 return 0;
 838
 839         size = (fl->stripe_type == STRIPE_SPARSE) ?
 840                 fl->dsaddr->ds_num : fl->dsaddr->stripe_count;
 841
 842         if (cinfo->ds->nbuckets >= size) {
 843                 /* This assumes there is only one IOMODE_RW lseg.  What
 844                  * we really want to do is have a layout_hdr level
 845                  * dictionary of <multipath_list4, fh> keys, each
 846                  * associated with a struct list_head, populated by calls
 847                  * to filelayout_write_pagelist().
 848                  * */
 849                 return 0;
 850         }
 851
 852         buckets = kcalloc(size, sizeof(struct pnfs_commit_bucket),
 853                           gfp_flags);
 854         if (!buckets)
 855                 return -ENOMEM;
 856         for (i = 0; i < size; i++) {
 857                 INIT_LIST_HEAD(&buckets[i].written);
 858                 INIT_LIST_HEAD(&buckets[i].committing);
 859                 /* mark direct verifier as unset */
 860                 buckets[i].direct_verf.committed = NFS_INVALID_STABLE_HOW;
 861         }
 862
 863         spin_lock(cinfo->lock);
 864         if (cinfo->ds->nbuckets >= size)
 865                 goto out;
 866         for (i = 0; i < cinfo->ds->nbuckets; i++) {
 867                 list_splice(&cinfo->ds->buckets[i].written,
 868                             &buckets[i].written);
 869                 list_splice(&cinfo->ds->buckets[i].committing,
 870                             &buckets[i].committing);
 871                 buckets[i].direct_verf.committed =
 872                         cinfo->ds->buckets[i].direct_verf.committed;
 873                 buckets[i].wlseg = cinfo->ds->buckets[i].wlseg;
 874                 buckets[i].clseg = cinfo->ds->buckets[i].clseg;
 875         }
 876         swap(cinfo->ds->buckets, buckets);
 877         cinfo->ds->nbuckets = size;
 878 out:
 879         spin_unlock(cinfo->lock);
 880         kfree(buckets);
 881         return 0;
 882 }
 883
 884 static struct pnfs_layout_segment *
 885 filelayout_alloc_lseg(struct pnfs_layout_hdr *layoutid,
 886                       struct nfs4_layoutget_res *lgr,
 887                       gfp_t gfp_flags)
 888 {
 889         struct nfs4_filelayout_segment *fl;
 890         int rc;
 891         struct nfs4_deviceid id;
 892
 893         dprintk("--> %s\n", __func__);
 894         fl = kzalloc(sizeof(*fl), gfp_flags);
 895         if (!fl)
 896                 return NULL;
 897
 898         rc = filelayout_decode_layout(layoutid, fl, lgr, &id, gfp_flags);
 899         if (rc != 0 || filelayout_check_layout(layoutid, fl, lgr, &id, gfp_flags)) {
 900                 _filelayout_free_lseg(fl);
 901                 return NULL;
 902         }
 903         return &fl->generic_hdr;
 904 }
 905
 906 /*
 907  * filelayout_pg_test(). Called by nfs_can_coalesce_requests()
 908  *
 909  * Return 0 if @req cannot be coalesced into @pgio, otherwise return the number
 910  * of bytes (maximum @req->wb_bytes) that can be coalesced.
 911  */
 912 static size_t
 913 filelayout_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
 914                    struct nfs_page *req)
 915 {
 916         unsigned int size;
 917         u64 p_stripe, r_stripe;
 918         u32 stripe_offset;
 919         u64 segment_offset = pgio->pg_lseg->pls_range.offset;
 920         u32 stripe_unit = FILELAYOUT_LSEG(pgio->pg_lseg)->stripe_unit;
 921
 922         /* calls nfs_generic_pg_test */
 923         size = pnfs_generic_pg_test(pgio, prev, req);
 924         if (!size)
 925                 return 0;
 926
 927         /* see if req and prev are in the same stripe */
 928         if (prev) {
 929                 p_stripe = (u64)req_offset(prev) - segment_offset;
 930                 r_stripe = (u64)req_offset(req) - segment_offset;
 931                 do_div(p_stripe, stripe_unit);
 932                 do_div(r_stripe, stripe_unit);
 933
 934                 if (p_stripe != r_stripe)
 935                         return 0;
 936         }
 937
 938         /* calculate remaining bytes in the current stripe */
 939         div_u64_rem((u64)req_offset(req) - segment_offset,
 940                         stripe_unit,
 941                         &stripe_offset);
 942         WARN_ON_ONCE(stripe_offset > stripe_unit);
 943         if (stripe_offset >= stripe_unit)
 944                 return 0;
 945         return min(stripe_unit - (unsigned int)stripe_offset, size);
 946 }
 947
 948 static void
 949 filelayout_pg_init_read(struct nfs_pageio_descriptor *pgio,
 950                         struct nfs_page *req)
 951 {
 952         if (!pgio->pg_lseg)
 953                 pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
 954                                            req->wb_context,
 955                                            0,
 956                                            NFS4_MAX_UINT64,
 957                                            IOMODE_READ,
 958                                            GFP_KERNEL);
 959         /* If no lseg, fall back to read through mds */
 960         if (pgio->pg_lseg == NULL)
 961                 nfs_pageio_reset_read_mds(pgio);
 962 }
 963
 964 static void
 965 filelayout_pg_init_write(struct nfs_pageio_descriptor *pgio,
 966                          struct nfs_page *req)
 967 {
 968         struct nfs_commit_info cinfo;
 969         int status;
 970
 971         if (!pgio->pg_lseg)
 972                 pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
 973                                            req->wb_context,
 974                                            0,
 975                                            NFS4_MAX_UINT64,
 976                                            IOMODE_RW,
 977                                            GFP_NOFS);
 978         /* If no lseg, fall back to write through mds */
 979         if (pgio->pg_lseg == NULL)
 980                 goto out_mds;
 981         nfs_init_cinfo(&cinfo, pgio->pg_inode, pgio->pg_dreq);
 982         status = filelayout_alloc_commit_info(pgio->pg_lseg, &cinfo, GFP_NOFS);
 983         if (status < 0) {
 984                 pnfs_put_lseg(pgio->pg_lseg);
 985                 pgio->pg_lseg = NULL;
 986                 goto out_mds;
 987         }
 988         return;
 989 out_mds:
 990         nfs_pageio_reset_write_mds(pgio);
 991 }
 992
 993 static const struct nfs_pageio_ops filelayout_pg_read_ops = {
 994         .pg_init = filelayout_pg_init_read,
 995         .pg_test = filelayout_pg_test,
 996         .pg_doio = pnfs_generic_pg_readpages,
 997 };
 998
 999 static const struct nfs_pageio_ops filelayout_pg_write_ops = {
1000         .pg_init = filelayout_pg_init_write,
1001         .pg_test = filelayout_pg_test,
1002         .pg_doio = pnfs_generic_pg_writepages,
1003 };
1004
1005 static u32 select_bucket_index(struct nfs4_filelayout_segment *fl, u32 j)
1006 {
1007         if (fl->stripe_type == STRIPE_SPARSE)
1008                 return nfs4_fl_calc_ds_index(&fl->generic_hdr, j);
1009         else
1010                 return j;
1011 }
1012
1013 /* The generic layer is about to remove the req from the commit list.
1014  * If this will make the bucket empty, it will need to put the lseg reference.
1015  * Note this is must be called holding the inode (/cinfo) lock
1016  */
1017 static void
1018 filelayout_clear_request_commit(struct nfs_page *req,
1019                                 struct nfs_commit_info *cinfo)
1020 {
1021         struct pnfs_layout_segment *freeme = NULL;
1022
1023         if (!test_and_clear_bit(PG_COMMIT_TO_DS, &req->wb_flags))
1024                 goto out;
1025         cinfo->ds->nwritten--;
1026         if (list_is_singular(&req->wb_list)) {
1027                 struct pnfs_commit_bucket *bucket;
1028
1029                 bucket = list_first_entry(&req->wb_list,
1030                                           struct pnfs_commit_bucket,
1031                                           written);
1032                 freeme = bucket->wlseg;
1033                 bucket->wlseg = NULL;
1034         }
1035 out:
1036         nfs_request_remove_commit_list(req, cinfo);
1037         pnfs_put_lseg_async(freeme);
1038 }
1039
1040 static void
1041 filelayout_mark_request_commit(struct nfs_page *req,
1042                                struct pnfs_layout_segment *lseg,
1043                                struct nfs_commit_info *cinfo)
1044
1045 {
1046         struct nfs4_filelayout_segment *fl = FILELAYOUT_LSEG(lseg);
1047         u32 i, j;
1048         struct list_head *list;
1049         struct pnfs_commit_bucket *buckets;
1050
1051         if (fl->commit_through_mds) {
1052                 list = &cinfo->mds->list;
1053                 spin_lock(cinfo->lock);
1054                 goto mds_commit;
1055         }
1056
1057         /* Note that we are calling nfs4_fl_calc_j_index on each page
1058          * that ends up being committed to a data server.  An attractive
1059          * alternative is to add a field to nfs_write_data and nfs_page
1060          * to store the value calculated in filelayout_write_pagelist
1061          * and just use that here.
1062          */
1063         j = nfs4_fl_calc_j_index(lseg, req_offset(req));
1064         i = select_bucket_index(fl, j);
1065         spin_lock(cinfo->lock);
1066         buckets = cinfo->ds->buckets;
1067         list = &buckets[i].written;
1068         if (list_empty(list)) {
1069                 /* Non-empty buckets hold a reference on the lseg.  That ref
1070                  * is normally transferred to the COMMIT call and released
1071                  * there.  It could also be released if the last req is pulled
1072                  * off due to a rewrite, in which case it will be done in
1073                  * filelayout_clear_request_commit
1074                  */
1075                 buckets[i].wlseg = pnfs_get_lseg(lseg);
1076         }
1077         set_bit(PG_COMMIT_TO_DS, &req->wb_flags);
1078         cinfo->ds->nwritten++;
1079
1080 mds_commit:
1081         /* nfs_request_add_commit_list(). We need to add req to list without
1082          * dropping cinfo lock.
1083          */
1084         set_bit(PG_CLEAN, &(req)->wb_flags);
1085         nfs_list_add_request(req, list);
1086         cinfo->mds->ncommit++;
1087         spin_unlock(cinfo->lock);
1088         if (!cinfo->dreq) {
1089                 inc_zone_page_state(req->wb_page, NR_UNSTABLE_NFS);
1090                 inc_bdi_stat(page_file_mapping(req->wb_page)->backing_dev_info,
1091                              BDI_RECLAIMABLE);
1092                 __mark_inode_dirty(req->wb_context->dentry->d_inode,
1093                                    I_DIRTY_DATASYNC);
1094         }
1095 }
1096
1097 static u32 calc_ds_index_from_commit(struct pnfs_layout_segment *lseg, u32 i)
1098 {
1099         struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
1100
1101         if (flseg->stripe_type == STRIPE_SPARSE)
1102                 return i;
1103         else
1104                 return nfs4_fl_calc_ds_index(lseg, i);
1105 }
1106
1107 static struct nfs_fh *
1108 select_ds_fh_from_commit(struct pnfs_layout_segment *lseg, u32 i)
1109 {
1110         struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
1111
1112         if (flseg->stripe_type == STRIPE_SPARSE) {
1113                 if (flseg->num_fh == 1)
1114                         i = 0;
1115                 else if (flseg->num_fh == 0)
1116                         /* Use the MDS OPEN fh set in nfs_read_rpcsetup */
1117                         return NULL;
1118         }
1119         return flseg->fh_array[i];
1120 }
1121
1122 static int filelayout_initiate_commit(struct nfs_commit_data *data, int how)
1123 {
1124         struct pnfs_layout_segment *lseg = data->lseg;
1125         struct nfs4_pnfs_ds *ds;
1126         struct rpc_clnt *ds_clnt;
1127         u32 idx;
1128         struct nfs_fh *fh;
1129
1130         idx = calc_ds_index_from_commit(lseg, data->ds_commit_index);
1131         ds = nfs4_fl_prepare_ds(lseg, idx);
1132         if (!ds)
1133                 goto out_err;
1134
1135         ds_clnt = nfs4_find_or_create_ds_client(ds->ds_clp, data->inode);
1136         if (IS_ERR(ds_clnt))
1137                 goto out_err;
1138
1139         dprintk("%s ino %lu, how %d cl_count %d\n", __func__,
1140                 data->inode->i_ino, how, atomic_read(&ds->ds_clp->cl_count));
1141         data->commit_done_cb = filelayout_commit_done_cb;
1142         atomic_inc(&ds->ds_clp->cl_count);
1143         data->ds_clp = ds->ds_clp;
1144         fh = select_ds_fh_from_commit(lseg, data->ds_commit_index);
1145         if (fh)
1146                 data->args.fh = fh;
1147         return nfs_initiate_commit(ds_clnt, data,
1148                                    &filelayout_commit_call_ops, how,
1149                                    RPC_TASK_SOFTCONN);
1150 out_err:
1151         prepare_to_resend_writes(data);
1152         filelayout_commit_release(data);
1153         return -EAGAIN;
1154 }
1155
1156 static int
1157 transfer_commit_list(struct list_head *src, struct list_head *dst,
1158                      struct nfs_commit_info *cinfo, int max)
1159 {
1160         struct nfs_page *req, *tmp;
1161         int ret = 0;
1162
1163         list_for_each_entry_safe(req, tmp, src, wb_list) {
1164                 if (!nfs_lock_request(req))
1165                         continue;
1166                 kref_get(&req->wb_kref);
1167                 if (cond_resched_lock(cinfo->lock))
1168                         list_safe_reset_next(req, tmp, wb_list);
1169                 nfs_request_remove_commit_list(req, cinfo);
1170                 clear_bit(PG_COMMIT_TO_DS, &req->wb_flags);
1171                 nfs_list_add_request(req, dst);
1172                 ret++;
1173                 if ((ret == max) && !cinfo->dreq)
1174                         break;
1175         }
1176         return ret;
1177 }
1178
1179 /* Note called with cinfo->lock held. */
1180 static int
1181 filelayout_scan_ds_commit_list(struct pnfs_commit_bucket *bucket,
1182                                struct nfs_commit_info *cinfo,
1183                                int max)
1184 {
1185         struct list_head *src = &bucket->written;
1186         struct list_head *dst = &bucket->committing;
1187         int ret;
1188
1189         ret = transfer_commit_list(src, dst, cinfo, max);
1190         if (ret) {
1191                 cinfo->ds->nwritten -= ret;
1192                 cinfo->ds->ncommitting += ret;
1193                 bucket->clseg = bucket->wlseg;
1194                 if (list_empty(src))
1195                         bucket->wlseg = NULL;
1196                 else
1197                         pnfs_get_lseg(bucket->clseg);
1198         }
1199         return ret;
1200 }
1201
1202 /* Move reqs from written to committing lists, returning count of number moved.
1203  * Note called with cinfo->lock held.
1204  */
1205 static int filelayout_scan_commit_lists(struct nfs_commit_info *cinfo,
1206                                         int max)
1207 {
1208         int i, rv = 0, cnt;
1209
1210         for (i = 0; i < cinfo->ds->nbuckets && max != 0; i++) {
1211                 cnt = filelayout_scan_ds_commit_list(&cinfo->ds->buckets[i],
1212                                                      cinfo, max);
1213                 max -= cnt;
1214                 rv += cnt;
1215         }
1216         return rv;
1217 }
1218
1219 /* Pull everything off the committing lists and dump into @dst */
1220 static void filelayout_recover_commit_reqs(struct list_head *dst,
1221                                            struct nfs_commit_info *cinfo)
1222 {
1223         struct pnfs_commit_bucket *b;
1224         struct pnfs_layout_segment *freeme;
1225         int i;
1226
1227 restart:
1228         spin_lock(cinfo->lock);
1229         for (i = 0, b = cinfo->ds->buckets; i < cinfo->ds->nbuckets; i++, b++) {
1230                 if (transfer_commit_list(&b->written, dst, cinfo, 0)) {
1231                         freeme = b->wlseg;
1232                         b->wlseg = NULL;
1233                         spin_unlock(cinfo->lock);
1234                         pnfs_put_lseg(freeme);
1235                         goto restart;
1236                 }
1237         }
1238         cinfo->ds->nwritten = 0;
1239         spin_unlock(cinfo->lock);
1240 }
1241
1242 /* filelayout_search_commit_reqs - Search lists in @cinfo for the head reqest
1243  *                                 for @page
1244  * @cinfo - commit info for current inode
1245  * @page - page to search for matching head request
1246  *
1247  * Returns a the head request if one is found, otherwise returns NULL.
1248  */
1249 static struct nfs_page *
1250 filelayout_search_commit_reqs(struct nfs_commit_info *cinfo, struct page *page)
1251 {
1252         struct nfs_page *freq, *t;
1253         struct pnfs_commit_bucket *b;
1254         int i;
1255
1256         /* Linearly search the commit lists for each bucket until a matching
1257          * request is found */
1258         for (i = 0, b = cinfo->ds->buckets; i < cinfo->ds->nbuckets; i++, b++) {
1259                 list_for_each_entry_safe(freq, t, &b->written, wb_list) {
1260                         if (freq->wb_page == page)
1261                                 return freq->wb_head;
1262                 }
1263                 list_for_each_entry_safe(freq, t, &b->committing, wb_list) {
1264                         if (freq->wb_page == page)
1265                                 return freq->wb_head;
1266                 }
1267         }
1268
1269         return NULL;
1270 }
1271
1272 static void filelayout_retry_commit(struct nfs_commit_info *cinfo, int idx)
1273 {
1274         struct pnfs_ds_commit_info *fl_cinfo = cinfo->ds;
1275         struct pnfs_commit_bucket *bucket;
1276         struct pnfs_layout_segment *freeme;
1277         int i;
1278
1279         for (i = idx; i < fl_cinfo->nbuckets; i++) {
1280                 bucket = &fl_cinfo->buckets[i];
1281                 if (list_empty(&bucket->committing))
1282                         continue;
1283                 nfs_retry_commit(&bucket->committing, bucket->clseg, cinfo);
1284                 spin_lock(cinfo->lock);
1285                 freeme = bucket->clseg;
1286                 bucket->clseg = NULL;
1287                 spin_unlock(cinfo->lock);
1288                 pnfs_put_lseg(freeme);
1289         }
1290 }
1291
1292 static unsigned int
1293 alloc_ds_commits(struct nfs_commit_info *cinfo, struct list_head *list)
1294 {
1295         struct pnfs_ds_commit_info *fl_cinfo;
1296         struct pnfs_commit_bucket *bucket;
1297         struct nfs_commit_data *data;
1298         int i;
1299         unsigned int nreq = 0;
1300
1301         fl_cinfo = cinfo->ds;
1302         bucket = fl_cinfo->buckets;
1303         for (i = 0; i < fl_cinfo->nbuckets; i++, bucket++) {
1304                 if (list_empty(&bucket->committing))
1305                         continue;
1306                 data = nfs_commitdata_alloc();
1307                 if (!data)
1308                         break;
1309                 data->ds_commit_index = i;
1310                 spin_lock(cinfo->lock);
1311                 data->lseg = bucket->clseg;
1312                 bucket->clseg = NULL;
1313                 spin_unlock(cinfo->lock);
1314                 list_add(&data->pages, list);
1315                 nreq++;
1316         }
1317
1318         /* Clean up on error */
1319         filelayout_retry_commit(cinfo, i);
1320         /* Caller will clean up entries put on list */
1321         return nreq;
1322 }
1323
1324 /* This follows nfs_commit_list pretty closely */
1325 static int
1326 filelayout_commit_pagelist(struct inode *inode, struct list_head *mds_pages,
1327                            int how, struct nfs_commit_info *cinfo)
1328 {
1329         struct nfs_commit_data *data, *tmp;
1330         LIST_HEAD(list);
1331         unsigned int nreq = 0;
1332
1333         if (!list_empty(mds_pages)) {
1334                 data = nfs_commitdata_alloc();
1335                 if (data != NULL) {
1336                         data->lseg = NULL;
1337                         list_add(&data->pages, &list);
1338                         nreq++;
1339                 } else {
1340                         nfs_retry_commit(mds_pages, NULL, cinfo);
1341                         filelayout_retry_commit(cinfo, 0);
1342                         cinfo->completion_ops->error_cleanup(NFS_I(inode));
1343                         return -ENOMEM;
1344                 }
1345         }
1346
1347         nreq += alloc_ds_commits(cinfo, &list);
1348
1349         if (nreq == 0) {
1350                 cinfo->completion_ops->error_cleanup(NFS_I(inode));
1351                 goto out;
1352         }
1353
1354         atomic_add(nreq, &cinfo->mds->rpcs_out);
1355
1356         list_for_each_entry_safe(data, tmp, &list, pages) {
1357                 list_del_init(&data->pages);
1358                 if (!data->lseg) {
1359                         nfs_init_commit(data, mds_pages, NULL, cinfo);
1360                         nfs_initiate_commit(NFS_CLIENT(inode), data,
1361                                             data->mds_ops, how, 0);
1362                 } else {
1363                         struct pnfs_commit_bucket *buckets;
1364
1365                         buckets = cinfo->ds->buckets;
1366                         nfs_init_commit(data, &buckets[data->ds_commit_index].committing, data->lseg, cinfo);
1367                         filelayout_initiate_commit(data, how);
1368                 }
1369         }
1370 out:
1371         cinfo->ds->ncommitting = 0;
1372         return PNFS_ATTEMPTED;
1373 }
1374
1375 static void
1376 filelayout_free_deveiceid_node(struct nfs4_deviceid_node *d)
1377 {
1378         nfs4_fl_free_deviceid(container_of(d, struct nfs4_file_layout_dsaddr, id_node));
1379 }
1380
1381 static struct pnfs_layout_hdr *
1382 filelayout_alloc_layout_hdr(struct inode *inode, gfp_t gfp_flags)
1383 {
1384         struct nfs4_filelayout *flo;
1385
1386         flo = kzalloc(sizeof(*flo), gfp_flags);
1387         return flo != NULL ? &flo->generic_hdr : NULL;
1388 }
1389
1390 static void
1391 filelayout_free_layout_hdr(struct pnfs_layout_hdr *lo)
1392 {
1393         kfree(FILELAYOUT_FROM_HDR(lo));
1394 }
1395
1396 static struct pnfs_ds_commit_info *
1397 filelayout_get_ds_info(struct inode *inode)
1398 {
1399         struct pnfs_layout_hdr *layout = NFS_I(inode)->layout;
1400
1401         if (layout == NULL)
1402                 return NULL;
1403         else
1404                 return &FILELAYOUT_FROM_HDR(layout)->commit_info;
1405 }
1406
1407 static struct pnfs_layoutdriver_type filelayout_type = {
1408         .id                     = LAYOUT_NFSV4_1_FILES,
1409         .name                   = "LAYOUT_NFSV4_1_FILES",
1410         .owner                  = THIS_MODULE,
1411         .alloc_layout_hdr       = filelayout_alloc_layout_hdr,
1412         .free_layout_hdr        = filelayout_free_layout_hdr,
1413         .alloc_lseg             = filelayout_alloc_lseg,
1414         .free_lseg              = filelayout_free_lseg,
1415         .pg_read_ops            = &filelayout_pg_read_ops,
1416         .pg_write_ops           = &filelayout_pg_write_ops,
1417         .get_ds_info            = &filelayout_get_ds_info,
1418         .mark_request_commit    = filelayout_mark_request_commit,
1419         .clear_request_commit   = filelayout_clear_request_commit,
1420         .scan_commit_lists      = filelayout_scan_commit_lists,
1421         .recover_commit_reqs    = filelayout_recover_commit_reqs,
1422         .search_commit_reqs     = filelayout_search_commit_reqs,
1423         .commit_pagelist        = filelayout_commit_pagelist,
1424         .read_pagelist          = filelayout_read_pagelist,
1425         .write_pagelist         = filelayout_write_pagelist,
1426         .free_deviceid_node     = filelayout_free_deveiceid_node,
1427 };
1428
1429 static int __init nfs4filelayout_init(void)
1430 {
1431         printk(KERN_INFO "%s: NFSv4 File Layout Driver Registering...\n",
1432                __func__);
1433         return pnfs_register_layoutdriver(&filelayout_type);
1434 }
1435
1436 static void __exit nfs4filelayout_exit(void)
1437 {
1438         printk(KERN_INFO "%s: NFSv4 File Layout Driver Unregistering...\n",
1439                __func__);
1440         pnfs_unregister_layoutdriver(&filelayout_type);
1441 }
1442
1443 MODULE_ALIAS("nfs-layouttype4-1");
1444
1445 module_init(nfs4filelayout_init);
1446 module_exit(nfs4filelayout_exit);