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
  35 #include "internal.h"
  36 #include "nfs4filelayout.h"
  37
  38 #define NFSDBG_FACILITY         NFSDBG_PNFS_LD
  39
  40 MODULE_LICENSE("GPL");
  41 MODULE_AUTHOR("Dean Hildebrand <dhildebz@umich.edu>");
  42 MODULE_DESCRIPTION("The NFSv4 file layout driver");
  43
  44 #define FILELAYOUT_POLL_RETRY_MAX     (15*HZ)
  45
  46 static loff_t
  47 filelayout_get_dense_offset(struct nfs4_filelayout_segment *flseg,
  48                             loff_t offset)
  49 {
  50         u32 stripe_width = flseg->stripe_unit * flseg->dsaddr->stripe_count;
  51         u64 tmp;
  52
  53         offset -= flseg->pattern_offset;
  54         tmp = offset;
  55         do_div(tmp, stripe_width);
  56
  57         return tmp * flseg->stripe_unit + do_div(offset, flseg->stripe_unit);
  58 }
  59
  60 /* This function is used by the layout driver to calculate the
  61  * offset of the file on the dserver based on whether the
  62  * layout type is STRIPE_DENSE or STRIPE_SPARSE
  63  */
  64 static loff_t
  65 filelayout_get_dserver_offset(struct pnfs_layout_segment *lseg, loff_t offset)
  66 {
  67         struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
  68
  69         switch (flseg->stripe_type) {
  70         case STRIPE_SPARSE:
  71                 return offset;
  72
  73         case STRIPE_DENSE:
  74                 return filelayout_get_dense_offset(flseg, offset);
  75         }
  76
  77         BUG();
  78 }
  79
  80 /* For data server errors we don't recover from */
  81 static void
  82 filelayout_set_lo_fail(struct pnfs_layout_segment *lseg)
  83 {
  84         if (lseg->pls_range.iomode == IOMODE_RW) {
  85                 dprintk("%s Setting layout IOMODE_RW fail bit\n", __func__);
  86                 set_bit(lo_fail_bit(IOMODE_RW), &lseg->pls_layout->plh_flags);
  87         } else {
  88                 dprintk("%s Setting layout IOMODE_READ fail bit\n", __func__);
  89                 set_bit(lo_fail_bit(IOMODE_READ), &lseg->pls_layout->plh_flags);
  90         }
  91 }
  92
  93 static int filelayout_async_handle_error(struct rpc_task *task,
  94                                          struct nfs4_state *state,
  95                                          struct nfs_client *clp,
  96                                          int *reset)
  97 {
  98         if (task->tk_status >= 0)
  99                 return 0;
 100
 101         *reset = 0;
 102
 103         switch (task->tk_status) {
 104         case -NFS4ERR_BADSESSION:
 105         case -NFS4ERR_BADSLOT:
 106         case -NFS4ERR_BAD_HIGH_SLOT:
 107         case -NFS4ERR_DEADSESSION:
 108         case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
 109         case -NFS4ERR_SEQ_FALSE_RETRY:
 110         case -NFS4ERR_SEQ_MISORDERED:
 111                 dprintk("%s ERROR %d, Reset session. Exchangeid "
 112                         "flags 0x%x\n", __func__, task->tk_status,
 113                         clp->cl_exchange_flags);
 114                 nfs4_schedule_session_recovery(clp->cl_session);
 115                 break;
 116         case -NFS4ERR_DELAY:
 117         case -NFS4ERR_GRACE:
 118         case -EKEYEXPIRED:
 119                 rpc_delay(task, FILELAYOUT_POLL_RETRY_MAX);
 120                 break;
 121         case -NFS4ERR_RETRY_UNCACHED_REP:
 122                 break;
 123         default:
 124                 dprintk("%s DS error. Retry through MDS %d\n", __func__,
 125                         task->tk_status);
 126                 *reset = 1;
 127                 break;
 128         }
 129         task->tk_status = 0;
 130         return -EAGAIN;
 131 }
 132
 133 /* NFS_PROTO call done callback routines */
 134
 135 static int filelayout_read_done_cb(struct rpc_task *task,
 136                                 struct nfs_read_data *data)
 137 {
 138         struct nfs_client *clp = data->ds_clp;
 139         int reset = 0;
 140
 141         dprintk("%s DS read\n", __func__);
 142
 143         if (filelayout_async_handle_error(task, data->args.context->state,
 144                                           data->ds_clp, &reset) == -EAGAIN) {
 145                 dprintk("%s calling restart ds_clp %p ds_clp->cl_session %p\n",
 146                         __func__, data->ds_clp, data->ds_clp->cl_session);
 147                 if (reset) {
 148                         filelayout_set_lo_fail(data->lseg);
 149                         nfs4_reset_read(task, data);
 150                         clp = NFS_SERVER(data->inode)->nfs_client;
 151                 }
 152                 nfs_restart_rpc(task, clp);
 153                 return -EAGAIN;
 154         }
 155
 156         return 0;
 157 }
 158
 159 /*
 160  * We reference the rpc_cred of the first WRITE that triggers the need for
 161  * a LAYOUTCOMMIT, and use it to send the layoutcommit compound.
 162  * rfc5661 is not clear about which credential should be used.
 163  */
 164 static void
 165 filelayout_set_layoutcommit(struct nfs_write_data *wdata)
 166 {
 167         if (FILELAYOUT_LSEG(wdata->lseg)->commit_through_mds ||
 168             wdata->res.verf->committed == NFS_FILE_SYNC)
 169                 return;
 170
 171         pnfs_set_layoutcommit(wdata);
 172         dprintk("%s ionde %lu pls_end_pos %lu\n", __func__, wdata->inode->i_ino,
 173                 (unsigned long) wdata->lseg->pls_end_pos);
 174 }
 175
 176 /*
 177  * Call ops for the async read/write cases
 178  * In the case of dense layouts, the offset needs to be reset to its
 179  * original value.
 180  */
 181 static void filelayout_read_prepare(struct rpc_task *task, void *data)
 182 {
 183         struct nfs_read_data *rdata = (struct nfs_read_data *)data;
 184
 185         rdata->read_done_cb = filelayout_read_done_cb;
 186
 187         if (nfs41_setup_sequence(rdata->ds_clp->cl_session,
 188                                 &rdata->args.seq_args, &rdata->res.seq_res,
 189                                 0, task))
 190                 return;
 191
 192         rpc_call_start(task);
 193 }
 194
 195 static void filelayout_read_call_done(struct rpc_task *task, void *data)
 196 {
 197         struct nfs_read_data *rdata = (struct nfs_read_data *)data;
 198
 199         dprintk("--> %s task->tk_status %d\n", __func__, task->tk_status);
 200
 201         /* Note this may cause RPC to be resent */
 202         rdata->mds_ops->rpc_call_done(task, data);
 203 }
 204
 205 static void filelayout_read_release(void *data)
 206 {
 207         struct nfs_read_data *rdata = (struct nfs_read_data *)data;
 208
 209         rdata->mds_ops->rpc_release(data);
 210 }
 211
 212 static int filelayout_write_done_cb(struct rpc_task *task,
 213                                 struct nfs_write_data *data)
 214 {
 215         int reset = 0;
 216
 217         if (filelayout_async_handle_error(task, data->args.context->state,
 218                                           data->ds_clp, &reset) == -EAGAIN) {
 219                 struct nfs_client *clp;
 220
 221                 dprintk("%s calling restart ds_clp %p ds_clp->cl_session %p\n",
 222                         __func__, data->ds_clp, data->ds_clp->cl_session);
 223                 if (reset) {
 224                         filelayout_set_lo_fail(data->lseg);
 225                         nfs4_reset_write(task, data);
 226                         clp = NFS_SERVER(data->inode)->nfs_client;
 227                 } else
 228                         clp = data->ds_clp;
 229                 nfs_restart_rpc(task, clp);
 230                 return -EAGAIN;
 231         }
 232
 233         filelayout_set_layoutcommit(data);
 234         return 0;
 235 }
 236
 237 /* Fake up some data that will cause nfs_commit_release to retry the writes. */
 238 static void prepare_to_resend_writes(struct nfs_write_data *data)
 239 {
 240         struct nfs_page *first = nfs_list_entry(data->pages.next);
 241
 242         data->task.tk_status = 0;
 243         memcpy(data->verf.verifier, first->wb_verf.verifier,
 244                sizeof(first->wb_verf.verifier));
 245         data->verf.verifier[0]++; /* ensure verifier mismatch */
 246 }
 247
 248 static int filelayout_commit_done_cb(struct rpc_task *task,
 249                                      struct nfs_write_data *data)
 250 {
 251         int reset = 0;
 252
 253         if (filelayout_async_handle_error(task, data->args.context->state,
 254                                           data->ds_clp, &reset) == -EAGAIN) {
 255                 dprintk("%s calling restart ds_clp %p ds_clp->cl_session %p\n",
 256                         __func__, data->ds_clp, data->ds_clp->cl_session);
 257                 if (reset) {
 258                         prepare_to_resend_writes(data);
 259                         filelayout_set_lo_fail(data->lseg);
 260                 } else
 261                         nfs_restart_rpc(task, data->ds_clp);
 262                 return -EAGAIN;
 263         }
 264
 265         return 0;
 266 }
 267
 268 static void filelayout_write_prepare(struct rpc_task *task, void *data)
 269 {
 270         struct nfs_write_data *wdata = (struct nfs_write_data *)data;
 271
 272         if (nfs41_setup_sequence(wdata->ds_clp->cl_session,
 273                                 &wdata->args.seq_args, &wdata->res.seq_res,
 274                                 0, task))
 275                 return;
 276
 277         rpc_call_start(task);
 278 }
 279
 280 static void filelayout_write_call_done(struct rpc_task *task, void *data)
 281 {
 282         struct nfs_write_data *wdata = (struct nfs_write_data *)data;
 283
 284         /* Note this may cause RPC to be resent */
 285         wdata->mds_ops->rpc_call_done(task, data);
 286 }
 287
 288 static void filelayout_write_release(void *data)
 289 {
 290         struct nfs_write_data *wdata = (struct nfs_write_data *)data;
 291
 292         wdata->mds_ops->rpc_release(data);
 293 }
 294
 295 static void filelayout_commit_release(void *data)
 296 {
 297         struct nfs_write_data *wdata = (struct nfs_write_data *)data;
 298
 299         nfs_commit_release_pages(wdata);
 300         if (atomic_dec_and_test(&NFS_I(wdata->inode)->commits_outstanding))
 301                 nfs_commit_clear_lock(NFS_I(wdata->inode));
 302         nfs_commitdata_release(wdata);
 303 }
 304
 305 struct rpc_call_ops filelayout_read_call_ops = {
 306         .rpc_call_prepare = filelayout_read_prepare,
 307         .rpc_call_done = filelayout_read_call_done,
 308         .rpc_release = filelayout_read_release,
 309 };
 310
 311 struct rpc_call_ops filelayout_write_call_ops = {
 312         .rpc_call_prepare = filelayout_write_prepare,
 313         .rpc_call_done = filelayout_write_call_done,
 314         .rpc_release = filelayout_write_release,
 315 };
 316
 317 struct rpc_call_ops filelayout_commit_call_ops = {
 318         .rpc_call_prepare = filelayout_write_prepare,
 319         .rpc_call_done = filelayout_write_call_done,
 320         .rpc_release = filelayout_commit_release,
 321 };
 322
 323 static enum pnfs_try_status
 324 filelayout_read_pagelist(struct nfs_read_data *data)
 325 {
 326         struct pnfs_layout_segment *lseg = data->lseg;
 327         struct nfs4_pnfs_ds *ds;
 328         loff_t offset = data->args.offset;
 329         u32 j, idx;
 330         struct nfs_fh *fh;
 331         int status;
 332
 333         dprintk("--> %s ino %lu pgbase %u req %Zu@%llu\n",
 334                 __func__, data->inode->i_ino,
 335                 data->args.pgbase, (size_t)data->args.count, offset);
 336
 337         if (test_bit(NFS_DEVICEID_INVALID, &FILELAYOUT_DEVID_NODE(lseg)->flags))
 338                 return PNFS_NOT_ATTEMPTED;
 339
 340         /* Retrieve the correct rpc_client for the byte range */
 341         j = nfs4_fl_calc_j_index(lseg, offset);
 342         idx = nfs4_fl_calc_ds_index(lseg, j);
 343         ds = nfs4_fl_prepare_ds(lseg, idx);
 344         if (!ds) {
 345                 /* Either layout fh index faulty, or ds connect failed */
 346                 set_bit(lo_fail_bit(IOMODE_RW), &lseg->pls_layout->plh_flags);
 347                 set_bit(lo_fail_bit(IOMODE_READ), &lseg->pls_layout->plh_flags);
 348                 return PNFS_NOT_ATTEMPTED;
 349         }
 350         dprintk("%s USE DS: %s\n", __func__, ds->ds_remotestr);
 351
 352         /* No multipath support. Use first DS */
 353         data->ds_clp = ds->ds_clp;
 354         fh = nfs4_fl_select_ds_fh(lseg, j);
 355         if (fh)
 356                 data->args.fh = fh;
 357
 358         data->args.offset = filelayout_get_dserver_offset(lseg, offset);
 359         data->mds_offset = offset;
 360
 361         /* Perform an asynchronous read to ds */
 362         status = nfs_initiate_read(data, ds->ds_clp->cl_rpcclient,
 363                                    &filelayout_read_call_ops);
 364         BUG_ON(status != 0);
 365         return PNFS_ATTEMPTED;
 366 }
 367
 368 /* Perform async writes. */
 369 static enum pnfs_try_status
 370 filelayout_write_pagelist(struct nfs_write_data *data, int sync)
 371 {
 372         struct pnfs_layout_segment *lseg = data->lseg;
 373         struct nfs4_pnfs_ds *ds;
 374         loff_t offset = data->args.offset;
 375         u32 j, idx;
 376         struct nfs_fh *fh;
 377         int status;
 378
 379         if (test_bit(NFS_DEVICEID_INVALID, &FILELAYOUT_DEVID_NODE(lseg)->flags))
 380                 return PNFS_NOT_ATTEMPTED;
 381
 382         /* Retrieve the correct rpc_client for the byte range */
 383         j = nfs4_fl_calc_j_index(lseg, offset);
 384         idx = nfs4_fl_calc_ds_index(lseg, j);
 385         ds = nfs4_fl_prepare_ds(lseg, idx);
 386         if (!ds) {
 387                 printk(KERN_ERR "%s: prepare_ds failed, use MDS\n", __func__);
 388                 set_bit(lo_fail_bit(IOMODE_RW), &lseg->pls_layout->plh_flags);
 389                 set_bit(lo_fail_bit(IOMODE_READ), &lseg->pls_layout->plh_flags);
 390                 return PNFS_NOT_ATTEMPTED;
 391         }
 392         dprintk("%s ino %lu sync %d req %Zu@%llu DS: %s\n", __func__,
 393                 data->inode->i_ino, sync, (size_t) data->args.count, offset,
 394                 ds->ds_remotestr);
 395
 396         data->write_done_cb = filelayout_write_done_cb;
 397         data->ds_clp = ds->ds_clp;
 398         fh = nfs4_fl_select_ds_fh(lseg, j);
 399         if (fh)
 400                 data->args.fh = fh;
 401         /*
 402          * Get the file offset on the dserver. Set the write offset to
 403          * this offset and save the original offset.
 404          */
 405         data->args.offset = filelayout_get_dserver_offset(lseg, offset);
 406
 407         /* Perform an asynchronous write */
 408         status = nfs_initiate_write(data, ds->ds_clp->cl_rpcclient,
 409                                     &filelayout_write_call_ops, sync);
 410         BUG_ON(status != 0);
 411         return PNFS_ATTEMPTED;
 412 }
 413
 414 /*
 415  * filelayout_check_layout()
 416  *
 417  * Make sure layout segment parameters are sane WRT the device.
 418  * At this point no generic layer initialization of the lseg has occurred,
 419  * and nothing has been added to the layout_hdr cache.
 420  *
 421  */
 422 static int
 423 filelayout_check_layout(struct pnfs_layout_hdr *lo,
 424                         struct nfs4_filelayout_segment *fl,
 425                         struct nfs4_layoutget_res *lgr,
 426                         struct nfs4_deviceid *id,
 427                         gfp_t gfp_flags)
 428 {
 429         struct nfs4_deviceid_node *d;
 430         struct nfs4_file_layout_dsaddr *dsaddr;
 431         int status = -EINVAL;
 432         struct nfs_server *nfss = NFS_SERVER(lo->plh_inode);
 433
 434         dprintk("--> %s\n", __func__);
 435
 436         /* FIXME: remove this check when layout segment support is added */
 437         if (lgr->range.offset != 0 ||
 438             lgr->range.length != NFS4_MAX_UINT64) {
 439                 dprintk("%s Only whole file layouts supported. Use MDS i/o\n",
 440                         __func__);
 441                 goto out;
 442         }
 443
 444         if (fl->pattern_offset > lgr->range.offset) {
 445                 dprintk("%s pattern_offset %lld too large\n",
 446                                 __func__, fl->pattern_offset);
 447                 goto out;
 448         }
 449
 450         if (!fl->stripe_unit || fl->stripe_unit % PAGE_SIZE) {
 451                 dprintk("%s Invalid stripe unit (%u)\n",
 452                         __func__, fl->stripe_unit);
 453                 goto out;
 454         }
 455
 456         /* find and reference the deviceid */
 457         d = nfs4_find_get_deviceid(NFS_SERVER(lo->plh_inode)->pnfs_curr_ld,
 458                                    NFS_SERVER(lo->plh_inode)->nfs_client, id);
 459         if (d == NULL) {
 460                 dsaddr = get_device_info(lo->plh_inode, id, gfp_flags);
 461                 if (dsaddr == NULL)
 462                         goto out;
 463         } else
 464                 dsaddr = container_of(d, struct nfs4_file_layout_dsaddr, id_node);
 465         /* Found deviceid is being reaped */
 466         if (test_bit(NFS_DEVICEID_INVALID, &dsaddr->id_node.flags))
 467                         goto out_put;
 468
 469         fl->dsaddr = dsaddr;
 470
 471         if (fl->first_stripe_index < 0 ||
 472             fl->first_stripe_index >= dsaddr->stripe_count) {
 473                 dprintk("%s Bad first_stripe_index %d\n",
 474                                 __func__, fl->first_stripe_index);
 475                 goto out_put;
 476         }
 477
 478         if ((fl->stripe_type == STRIPE_SPARSE &&
 479             fl->num_fh > 1 && fl->num_fh != dsaddr->ds_num) ||
 480             (fl->stripe_type == STRIPE_DENSE &&
 481             fl->num_fh != dsaddr->stripe_count)) {
 482                 dprintk("%s num_fh %u not valid for given packing\n",
 483                         __func__, fl->num_fh);
 484                 goto out_put;
 485         }
 486
 487         if (fl->stripe_unit % nfss->rsize || fl->stripe_unit % nfss->wsize) {
 488                 dprintk("%s Stripe unit (%u) not aligned with rsize %u "
 489                         "wsize %u\n", __func__, fl->stripe_unit, nfss->rsize,
 490                         nfss->wsize);
 491         }
 492
 493         status = 0;
 494 out:
 495         dprintk("--> %s returns %d\n", __func__, status);
 496         return status;
 497 out_put:
 498         nfs4_fl_put_deviceid(dsaddr);
 499         goto out;
 500 }
 501
 502 static void filelayout_free_fh_array(struct nfs4_filelayout_segment *fl)
 503 {
 504         int i;
 505
 506         for (i = 0; i < fl->num_fh; i++) {
 507                 if (!fl->fh_array[i])
 508                         break;
 509                 kfree(fl->fh_array[i]);
 510         }
 511         kfree(fl->fh_array);
 512         fl->fh_array = NULL;
 513 }
 514
 515 static void
 516 _filelayout_free_lseg(struct nfs4_filelayout_segment *fl)
 517 {
 518         filelayout_free_fh_array(fl);
 519         kfree(fl);
 520 }
 521
 522 static int
 523 filelayout_decode_layout(struct pnfs_layout_hdr *flo,
 524                          struct nfs4_filelayout_segment *fl,
 525                          struct nfs4_layoutget_res *lgr,
 526                          struct nfs4_deviceid *id,
 527                          gfp_t gfp_flags)
 528 {
 529         struct xdr_stream stream;
 530         struct xdr_buf buf;
 531         struct page *scratch;
 532         __be32 *p;
 533         uint32_t nfl_util;
 534         int i;
 535
 536         dprintk("%s: set_layout_map Begin\n", __func__);
 537
 538         scratch = alloc_page(gfp_flags);
 539         if (!scratch)
 540                 return -ENOMEM;
 541
 542         xdr_init_decode_pages(&stream, &buf, lgr->layoutp->pages, lgr->layoutp->len);
 543         xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
 544
 545         /* 20 = ufl_util (4), first_stripe_index (4), pattern_offset (8),
 546          * num_fh (4) */
 547         p = xdr_inline_decode(&stream, NFS4_DEVICEID4_SIZE + 20);
 548         if (unlikely(!p))
 549                 goto out_err;
 550
 551         memcpy(id, p, sizeof(*id));
 552         p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);
 553         nfs4_print_deviceid(id);
 554
 555         nfl_util = be32_to_cpup(p++);
 556         if (nfl_util & NFL4_UFLG_COMMIT_THRU_MDS)
 557                 fl->commit_through_mds = 1;
 558         if (nfl_util & NFL4_UFLG_DENSE)
 559                 fl->stripe_type = STRIPE_DENSE;
 560         else
 561                 fl->stripe_type = STRIPE_SPARSE;
 562         fl->stripe_unit = nfl_util & ~NFL4_UFLG_MASK;
 563
 564         fl->first_stripe_index = be32_to_cpup(p++);
 565         p = xdr_decode_hyper(p, &fl->pattern_offset);
 566         fl->num_fh = be32_to_cpup(p++);
 567
 568         dprintk("%s: nfl_util 0x%X num_fh %u fsi %u po %llu\n",
 569                 __func__, nfl_util, fl->num_fh, fl->first_stripe_index,
 570                 fl->pattern_offset);
 571
 572         /* Note that a zero value for num_fh is legal for STRIPE_SPARSE.
 573          * Futher checking is done in filelayout_check_layout */
 574         if (fl->num_fh < 0 || fl->num_fh >
 575             max(NFS4_PNFS_MAX_STRIPE_CNT, NFS4_PNFS_MAX_MULTI_CNT))
 576                 goto out_err;
 577
 578         if (fl->num_fh > 0) {
 579                 fl->fh_array = kzalloc(fl->num_fh * sizeof(struct nfs_fh *),
 580                                        gfp_flags);
 581                 if (!fl->fh_array)
 582                         goto out_err;
 583         }
 584
 585         for (i = 0; i < fl->num_fh; i++) {
 586                 /* Do we want to use a mempool here? */
 587                 fl->fh_array[i] = kmalloc(sizeof(struct nfs_fh), gfp_flags);
 588                 if (!fl->fh_array[i])
 589                         goto out_err_free;
 590
 591                 p = xdr_inline_decode(&stream, 4);
 592                 if (unlikely(!p))
 593                         goto out_err_free;
 594                 fl->fh_array[i]->size = be32_to_cpup(p++);
 595                 if (sizeof(struct nfs_fh) < fl->fh_array[i]->size) {
 596                         printk(KERN_ERR "Too big fh %d received %d\n",
 597                                i, fl->fh_array[i]->size);
 598                         goto out_err_free;
 599                 }
 600
 601                 p = xdr_inline_decode(&stream, fl->fh_array[i]->size);
 602                 if (unlikely(!p))
 603                         goto out_err_free;
 604                 memcpy(fl->fh_array[i]->data, p, fl->fh_array[i]->size);
 605                 dprintk("DEBUG: %s: fh len %d\n", __func__,
 606                         fl->fh_array[i]->size);
 607         }
 608
 609         __free_page(scratch);
 610         return 0;
 611
 612 out_err_free:
 613         filelayout_free_fh_array(fl);
 614 out_err:
 615         __free_page(scratch);
 616         return -EIO;
 617 }
 618
 619 static void
 620 filelayout_free_lseg(struct pnfs_layout_segment *lseg)
 621 {
 622         struct nfs4_filelayout_segment *fl = FILELAYOUT_LSEG(lseg);
 623
 624         dprintk("--> %s\n", __func__);
 625         nfs4_fl_put_deviceid(fl->dsaddr);
 626         kfree(fl->commit_buckets);
 627         _filelayout_free_lseg(fl);
 628 }
 629
 630 static struct pnfs_layout_segment *
 631 filelayout_alloc_lseg(struct pnfs_layout_hdr *layoutid,
 632                       struct nfs4_layoutget_res *lgr,
 633                       gfp_t gfp_flags)
 634 {
 635         struct nfs4_filelayout_segment *fl;
 636         int rc;
 637         struct nfs4_deviceid id;
 638
 639         dprintk("--> %s\n", __func__);
 640         fl = kzalloc(sizeof(*fl), gfp_flags);
 641         if (!fl)
 642                 return NULL;
 643
 644         rc = filelayout_decode_layout(layoutid, fl, lgr, &id, gfp_flags);
 645         if (rc != 0 || filelayout_check_layout(layoutid, fl, lgr, &id, gfp_flags)) {
 646                 _filelayout_free_lseg(fl);
 647                 return NULL;
 648         }
 649
 650         /* This assumes there is only one IOMODE_RW lseg.  What
 651          * we really want to do is have a layout_hdr level
 652          * dictionary of <multipath_list4, fh> keys, each
 653          * associated with a struct list_head, populated by calls
 654          * to filelayout_write_pagelist().
 655          * */
 656         if ((!fl->commit_through_mds) && (lgr->range.iomode == IOMODE_RW)) {
 657                 int i;
 658                 int size = (fl->stripe_type == STRIPE_SPARSE) ?
 659                         fl->dsaddr->ds_num : fl->dsaddr->stripe_count;
 660
 661                 fl->commit_buckets = kcalloc(size, sizeof(struct list_head), gfp_flags);
 662                 if (!fl->commit_buckets) {
 663                         filelayout_free_lseg(&fl->generic_hdr);
 664                         return NULL;
 665                 }
 666                 fl->number_of_buckets = size;
 667                 for (i = 0; i < size; i++)
 668                         INIT_LIST_HEAD(&fl->commit_buckets[i]);
 669         }
 670         return &fl->generic_hdr;
 671 }
 672
 673 /*
 674  * filelayout_pg_test(). Called by nfs_can_coalesce_requests()
 675  *
 676  * return true  : coalesce page
 677  * return false : don't coalesce page
 678  */
 679 static bool
 680 filelayout_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
 681                    struct nfs_page *req)
 682 {
 683         u64 p_stripe, r_stripe;
 684         u32 stripe_unit;
 685
 686         if (!pnfs_generic_pg_test(pgio, prev, req) ||
 687             !nfs_generic_pg_test(pgio, prev, req))
 688                 return false;
 689
 690         p_stripe = (u64)prev->wb_index << PAGE_CACHE_SHIFT;
 691         r_stripe = (u64)req->wb_index << PAGE_CACHE_SHIFT;
 692         stripe_unit = FILELAYOUT_LSEG(pgio->pg_lseg)->stripe_unit;
 693
 694         do_div(p_stripe, stripe_unit);
 695         do_div(r_stripe, stripe_unit);
 696
 697         return (p_stripe == r_stripe);
 698 }
 699
 700 void
 701 filelayout_pg_init_read(struct nfs_pageio_descriptor *pgio,
 702                         struct nfs_page *req)
 703 {
 704         BUG_ON(pgio->pg_lseg != NULL);
 705
 706         pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
 707                                            req->wb_context,
 708                                            0,
 709                                            NFS4_MAX_UINT64,
 710                                            IOMODE_READ,
 711                                            GFP_KERNEL);
 712         /* If no lseg, fall back to read through mds */
 713         if (pgio->pg_lseg == NULL)
 714                 nfs_pageio_reset_read_mds(pgio);
 715 }
 716
 717 void
 718 filelayout_pg_init_write(struct nfs_pageio_descriptor *pgio,
 719                          struct nfs_page *req)
 720 {
 721         BUG_ON(pgio->pg_lseg != NULL);
 722
 723         pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
 724                                            req->wb_context,
 725                                            0,
 726                                            NFS4_MAX_UINT64,
 727                                            IOMODE_RW,
 728                                            GFP_NOFS);
 729         /* If no lseg, fall back to write through mds */
 730         if (pgio->pg_lseg == NULL)
 731                 nfs_pageio_reset_write_mds(pgio);
 732 }
 733
 734 static const struct nfs_pageio_ops filelayout_pg_read_ops = {
 735         .pg_init = filelayout_pg_init_read,
 736         .pg_test = filelayout_pg_test,
 737         .pg_doio = pnfs_generic_pg_readpages,
 738 };
 739
 740 static const struct nfs_pageio_ops filelayout_pg_write_ops = {
 741         .pg_init = filelayout_pg_init_write,
 742         .pg_test = filelayout_pg_test,
 743         .pg_doio = pnfs_generic_pg_writepages,
 744 };
 745
 746 static bool filelayout_mark_pnfs_commit(struct pnfs_layout_segment *lseg)
 747 {
 748         return !FILELAYOUT_LSEG(lseg)->commit_through_mds;
 749 }
 750
 751 static u32 select_bucket_index(struct nfs4_filelayout_segment *fl, u32 j)
 752 {
 753         if (fl->stripe_type == STRIPE_SPARSE)
 754                 return nfs4_fl_calc_ds_index(&fl->generic_hdr, j);
 755         else
 756                 return j;
 757 }
 758
 759 struct list_head *filelayout_choose_commit_list(struct nfs_page *req)
 760 {
 761         struct pnfs_layout_segment *lseg = req->wb_commit_lseg;
 762         struct nfs4_filelayout_segment *fl = FILELAYOUT_LSEG(lseg);
 763         u32 i, j;
 764         struct list_head *list;
 765
 766         /* Note that we are calling nfs4_fl_calc_j_index on each page
 767          * that ends up being committed to a data server.  An attractive
 768          * alternative is to add a field to nfs_write_data and nfs_page
 769          * to store the value calculated in filelayout_write_pagelist
 770          * and just use that here.
 771          */
 772         j = nfs4_fl_calc_j_index(lseg,
 773                                  (loff_t)req->wb_index << PAGE_CACHE_SHIFT);
 774         i = select_bucket_index(fl, j);
 775         list = &fl->commit_buckets[i];
 776         if (list_empty(list)) {
 777                 /* Non-empty buckets hold a reference on the lseg */
 778                 get_lseg(lseg);
 779         }
 780         return list;
 781 }
 782
 783 static u32 calc_ds_index_from_commit(struct pnfs_layout_segment *lseg, u32 i)
 784 {
 785         struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
 786
 787         if (flseg->stripe_type == STRIPE_SPARSE)
 788                 return i;
 789         else
 790                 return nfs4_fl_calc_ds_index(lseg, i);
 791 }
 792
 793 static struct nfs_fh *
 794 select_ds_fh_from_commit(struct pnfs_layout_segment *lseg, u32 i)
 795 {
 796         struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
 797
 798         if (flseg->stripe_type == STRIPE_SPARSE) {
 799                 if (flseg->num_fh == 1)
 800                         i = 0;
 801                 else if (flseg->num_fh == 0)
 802                         /* Use the MDS OPEN fh set in nfs_read_rpcsetup */
 803                         return NULL;
 804         }
 805         return flseg->fh_array[i];
 806 }
 807
 808 static int filelayout_initiate_commit(struct nfs_write_data *data, int how)
 809 {
 810         struct pnfs_layout_segment *lseg = data->lseg;
 811         struct nfs4_pnfs_ds *ds;
 812         u32 idx;
 813         struct nfs_fh *fh;
 814
 815         idx = calc_ds_index_from_commit(lseg, data->ds_commit_index);
 816         ds = nfs4_fl_prepare_ds(lseg, idx);
 817         if (!ds) {
 818                 printk(KERN_ERR "%s: prepare_ds failed, use MDS\n", __func__);
 819                 set_bit(lo_fail_bit(IOMODE_RW), &lseg->pls_layout->plh_flags);
 820                 set_bit(lo_fail_bit(IOMODE_READ), &lseg->pls_layout->plh_flags);
 821                 prepare_to_resend_writes(data);
 822                 data->mds_ops->rpc_release(data);
 823                 return -EAGAIN;
 824         }
 825         dprintk("%s ino %lu, how %d\n", __func__, data->inode->i_ino, how);
 826         data->write_done_cb = filelayout_commit_done_cb;
 827         data->ds_clp = ds->ds_clp;
 828         fh = select_ds_fh_from_commit(lseg, data->ds_commit_index);
 829         if (fh)
 830                 data->args.fh = fh;
 831         return nfs_initiate_commit(data, ds->ds_clp->cl_rpcclient,
 832                                    &filelayout_commit_call_ops, how);
 833 }
 834
 835 /*
 836  * This is only useful while we are using whole file layouts.
 837  */
 838 static struct pnfs_layout_segment *find_only_write_lseg(struct inode *inode)
 839 {
 840         struct pnfs_layout_segment *lseg, *rv = NULL;
 841
 842         spin_lock(&inode->i_lock);
 843         list_for_each_entry(lseg, &NFS_I(inode)->layout->plh_segs, pls_list)
 844                 if (lseg->pls_range.iomode == IOMODE_RW)
 845                         rv = get_lseg(lseg);
 846         spin_unlock(&inode->i_lock);
 847         return rv;
 848 }
 849
 850 static int alloc_ds_commits(struct inode *inode, struct list_head *list)
 851 {
 852         struct pnfs_layout_segment *lseg;
 853         struct nfs4_filelayout_segment *fl;
 854         struct nfs_write_data *data;
 855         int i, j;
 856
 857         /* Won't need this when non-whole file layout segments are supported
 858          * instead we will use a pnfs_layout_hdr structure */
 859         lseg = find_only_write_lseg(inode);
 860         if (!lseg)
 861                 return 0;
 862         fl = FILELAYOUT_LSEG(lseg);
 863         for (i = 0; i < fl->number_of_buckets; i++) {
 864                 if (list_empty(&fl->commit_buckets[i]))
 865                         continue;
 866                 data = nfs_commitdata_alloc();
 867                 if (!data)
 868                         goto out_bad;
 869                 data->ds_commit_index = i;
 870                 data->lseg = lseg;
 871                 list_add(&data->pages, list);
 872         }
 873         put_lseg(lseg);
 874         return 0;
 875
 876 out_bad:
 877         for (j = i; j < fl->number_of_buckets; j++) {
 878                 if (list_empty(&fl->commit_buckets[i]))
 879                         continue;
 880                 nfs_retry_commit(&fl->commit_buckets[i], lseg);
 881                 put_lseg(lseg);  /* associated with emptying bucket */
 882         }
 883         put_lseg(lseg);
 884         /* Caller will clean up entries put on list */
 885         return -ENOMEM;
 886 }
 887
 888 /* This follows nfs_commit_list pretty closely */
 889 static int
 890 filelayout_commit_pagelist(struct inode *inode, struct list_head *mds_pages,
 891                            int how)
 892 {
 893         struct nfs_write_data   *data, *tmp;
 894         LIST_HEAD(list);
 895
 896         if (!list_empty(mds_pages)) {
 897                 data = nfs_commitdata_alloc();
 898                 if (!data)
 899                         goto out_bad;
 900                 data->lseg = NULL;
 901                 list_add(&data->pages, &list);
 902         }
 903
 904         if (alloc_ds_commits(inode, &list))
 905                 goto out_bad;
 906
 907         list_for_each_entry_safe(data, tmp, &list, pages) {
 908                 list_del_init(&data->pages);
 909                 atomic_inc(&NFS_I(inode)->commits_outstanding);
 910                 if (!data->lseg) {
 911                         nfs_init_commit(data, mds_pages, NULL);
 912                         nfs_initiate_commit(data, NFS_CLIENT(inode),
 913                                             data->mds_ops, how);
 914                 } else {
 915                         nfs_init_commit(data, &FILELAYOUT_LSEG(data->lseg)->commit_buckets[data->ds_commit_index], data->lseg);
 916                         filelayout_initiate_commit(data, how);
 917                 }
 918         }
 919         return 0;
 920  out_bad:
 921         list_for_each_entry_safe(data, tmp, &list, pages) {
 922                 nfs_retry_commit(&data->pages, data->lseg);
 923                 list_del_init(&data->pages);
 924                 nfs_commit_free(data);
 925         }
 926         nfs_retry_commit(mds_pages, NULL);
 927         nfs_commit_clear_lock(NFS_I(inode));
 928         return -ENOMEM;
 929 }
 930
 931 static void
 932 filelayout_free_deveiceid_node(struct nfs4_deviceid_node *d)
 933 {
 934         nfs4_fl_free_deviceid(container_of(d, struct nfs4_file_layout_dsaddr, id_node));
 935 }
 936
 937 static struct pnfs_layoutdriver_type filelayout_type = {
 938         .id                     = LAYOUT_NFSV4_1_FILES,
 939         .name                   = "LAYOUT_NFSV4_1_FILES",
 940         .owner                  = THIS_MODULE,
 941         .alloc_lseg             = filelayout_alloc_lseg,
 942         .free_lseg              = filelayout_free_lseg,
 943         .pg_read_ops            = &filelayout_pg_read_ops,
 944         .pg_write_ops           = &filelayout_pg_write_ops,
 945         .mark_pnfs_commit       = filelayout_mark_pnfs_commit,
 946         .choose_commit_list     = filelayout_choose_commit_list,
 947         .commit_pagelist        = filelayout_commit_pagelist,
 948         .read_pagelist          = filelayout_read_pagelist,
 949         .write_pagelist         = filelayout_write_pagelist,
 950         .free_deviceid_node     = filelayout_free_deveiceid_node,
 951 };
 952
 953 static int __init nfs4filelayout_init(void)
 954 {
 955         printk(KERN_INFO "%s: NFSv4 File Layout Driver Registering...\n",
 956                __func__);
 957         return pnfs_register_layoutdriver(&filelayout_type);
 958 }
 959
 960 static void __exit nfs4filelayout_exit(void)
 961 {
 962         printk(KERN_INFO "%s: NFSv4 File Layout Driver Unregistering...\n",
 963                __func__);
 964         pnfs_unregister_layoutdriver(&filelayout_type);
 965 }
 966
 967 MODULE_ALIAS("nfs-layouttype4-1");
 968
 969 module_init(nfs4filelayout_init);
 970 module_exit(nfs4filelayout_exit);