fs/nfs/flexfilelayout/flexfilelayout.c

   1 /*
   2  * Module for pnfs flexfile layout driver.
   3  *
   4  * Copyright (c) 2014, Primary Data, Inc. All rights reserved.
   5  *
   6  * Tao Peng <bergwolf@primarydata.com>
   7  */
   8
   9 #include <linux/nfs_fs.h>
  10 #include <linux/nfs_page.h>
  11 #include <linux/module.h>
  12
  13 #include <linux/sunrpc/metrics.h>
  14
  15 #include "flexfilelayout.h"
  16 #include "../nfs4session.h"
  17 #include "../nfs4idmap.h"
  18 #include "../internal.h"
  19 #include "../delegation.h"
  20 #include "../nfs4trace.h"
  21 #include "../iostat.h"
  22 #include "../nfs.h"
  23 #include "../nfs42.h"
  24
  25 #define NFSDBG_FACILITY         NFSDBG_PNFS_LD
  26
  27 #define FF_LAYOUT_POLL_RETRY_MAX     (15*HZ)
  28 #define FF_LAYOUTRETURN_MAXERR 20
  29
  30
  31 static struct group_info        *ff_zero_group;
  32
  33 static void ff_layout_read_record_layoutstats_done(struct rpc_task *task,
  34                 struct nfs_pgio_header *hdr);
  35 static int ff_layout_mirror_prepare_stats(struct pnfs_layout_hdr *lo,
  36                                struct nfs42_layoutstat_devinfo *devinfo,
  37                                int dev_limit);
  38 static void ff_layout_encode_ff_layoutupdate(struct xdr_stream *xdr,
  39                               const struct nfs42_layoutstat_devinfo *devinfo,
  40                               struct nfs4_ff_layout_mirror *mirror);
  41
  42 static struct pnfs_layout_hdr *
  43 ff_layout_alloc_layout_hdr(struct inode *inode, gfp_t gfp_flags)
  44 {
  45         struct nfs4_flexfile_layout *ffl;
  46
  47         ffl = kzalloc(sizeof(*ffl), gfp_flags);
  48         if (ffl) {
  49                 INIT_LIST_HEAD(&ffl->error_list);
  50                 INIT_LIST_HEAD(&ffl->mirrors);
  51                 ffl->last_report_time = ktime_get();
  52                 return &ffl->generic_hdr;
  53         } else
  54                 return NULL;
  55 }
  56
  57 static void
  58 ff_layout_free_layout_hdr(struct pnfs_layout_hdr *lo)
  59 {
  60         struct nfs4_ff_layout_ds_err *err, *n;
  61
  62         list_for_each_entry_safe(err, n, &FF_LAYOUT_FROM_HDR(lo)->error_list,
  63                                  list) {
  64                 list_del(&err->list);
  65                 kfree(err);
  66         }
  67         kfree(FF_LAYOUT_FROM_HDR(lo));
  68 }
  69
  70 static int decode_pnfs_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
  71 {
  72         __be32 *p;
  73
  74         p = xdr_inline_decode(xdr, NFS4_STATEID_SIZE);
  75         if (unlikely(p == NULL))
  76                 return -ENOBUFS;
  77         stateid->type = NFS4_PNFS_DS_STATEID_TYPE;
  78         memcpy(stateid->data, p, NFS4_STATEID_SIZE);
  79         dprintk("%s: stateid id= [%x%x%x%x]\n", __func__,
  80                 p[0], p[1], p[2], p[3]);
  81         return 0;
  82 }
  83
  84 static int decode_deviceid(struct xdr_stream *xdr, struct nfs4_deviceid *devid)
  85 {
  86         __be32 *p;
  87
  88         p = xdr_inline_decode(xdr, NFS4_DEVICEID4_SIZE);
  89         if (unlikely(!p))
  90                 return -ENOBUFS;
  91         memcpy(devid, p, NFS4_DEVICEID4_SIZE);
  92         nfs4_print_deviceid(devid);
  93         return 0;
  94 }
  95
  96 static int decode_nfs_fh(struct xdr_stream *xdr, struct nfs_fh *fh)
  97 {
  98         __be32 *p;
  99
 100         p = xdr_inline_decode(xdr, 4);
 101         if (unlikely(!p))
 102                 return -ENOBUFS;
 103         fh->size = be32_to_cpup(p++);
 104         if (fh->size > sizeof(struct nfs_fh)) {
 105                 printk(KERN_ERR "NFS flexfiles: Too big fh received %d\n",
 106                        fh->size);
 107                 return -EOVERFLOW;
 108         }
 109         /* fh.data */
 110         p = xdr_inline_decode(xdr, fh->size);
 111         if (unlikely(!p))
 112                 return -ENOBUFS;
 113         memcpy(&fh->data, p, fh->size);
 114         dprintk("%s: fh len %d\n", __func__, fh->size);
 115
 116         return 0;
 117 }
 118
 119 /*
 120  * Currently only stringified uids and gids are accepted.
 121  * I.e., kerberos is not supported to the DSes, so no pricipals.
 122  *
 123  * That means that one common function will suffice, but when
 124  * principals are added, this should be split to accomodate
 125  * calls to both nfs_map_name_to_uid() and nfs_map_group_to_gid().
 126  */
 127 static int
 128 decode_name(struct xdr_stream *xdr, u32 *id)
 129 {
 130         __be32 *p;
 131         int len;
 132
 133         /* opaque_length(4)*/
 134         p = xdr_inline_decode(xdr, 4);
 135         if (unlikely(!p))
 136                 return -ENOBUFS;
 137         len = be32_to_cpup(p++);
 138         if (len < 0)
 139                 return -EINVAL;
 140
 141         dprintk("%s: len %u\n", __func__, len);
 142
 143         /* opaque body */
 144         p = xdr_inline_decode(xdr, len);
 145         if (unlikely(!p))
 146                 return -ENOBUFS;
 147
 148         if (!nfs_map_string_to_numeric((char *)p, len, id))
 149                 return -EINVAL;
 150
 151         return 0;
 152 }
 153
 154 static bool ff_mirror_match_fh(const struct nfs4_ff_layout_mirror *m1,
 155                 const struct nfs4_ff_layout_mirror *m2)
 156 {
 157         int i, j;
 158
 159         if (m1->fh_versions_cnt != m2->fh_versions_cnt)
 160                 return false;
 161         for (i = 0; i < m1->fh_versions_cnt; i++) {
 162                 bool found_fh = false;
 163                 for (j = 0; j < m2->fh_versions_cnt; j++) {
 164                         if (nfs_compare_fh(&m1->fh_versions[i],
 165                                         &m2->fh_versions[j]) == 0) {
 166                                 found_fh = true;
 167                                 break;
 168                         }
 169                 }
 170                 if (!found_fh)
 171                         return false;
 172         }
 173         return true;
 174 }
 175
 176 static struct nfs4_ff_layout_mirror *
 177 ff_layout_add_mirror(struct pnfs_layout_hdr *lo,
 178                 struct nfs4_ff_layout_mirror *mirror)
 179 {
 180         struct nfs4_flexfile_layout *ff_layout = FF_LAYOUT_FROM_HDR(lo);
 181         struct nfs4_ff_layout_mirror *pos;
 182         struct inode *inode = lo->plh_inode;
 183
 184         spin_lock(&inode->i_lock);
 185         list_for_each_entry(pos, &ff_layout->mirrors, mirrors) {
 186                 if (memcmp(&mirror->devid, &pos->devid, sizeof(pos->devid)) != 0)
 187                         continue;
 188                 if (!ff_mirror_match_fh(mirror, pos))
 189                         continue;
 190                 if (atomic_inc_not_zero(&pos->ref)) {
 191                         spin_unlock(&inode->i_lock);
 192                         return pos;
 193                 }
 194         }
 195         list_add(&mirror->mirrors, &ff_layout->mirrors);
 196         mirror->layout = lo;
 197         spin_unlock(&inode->i_lock);
 198         return mirror;
 199 }
 200
 201 static void
 202 ff_layout_remove_mirror(struct nfs4_ff_layout_mirror *mirror)
 203 {
 204         struct inode *inode;
 205         if (mirror->layout == NULL)
 206                 return;
 207         inode = mirror->layout->plh_inode;
 208         spin_lock(&inode->i_lock);
 209         list_del(&mirror->mirrors);
 210         spin_unlock(&inode->i_lock);
 211         mirror->layout = NULL;
 212 }
 213
 214 static struct nfs4_ff_layout_mirror *ff_layout_alloc_mirror(gfp_t gfp_flags)
 215 {
 216         struct nfs4_ff_layout_mirror *mirror;
 217
 218         mirror = kzalloc(sizeof(*mirror), gfp_flags);
 219         if (mirror != NULL) {
 220                 spin_lock_init(&mirror->lock);
 221                 atomic_set(&mirror->ref, 1);
 222                 INIT_LIST_HEAD(&mirror->mirrors);
 223         }
 224         return mirror;
 225 }
 226
 227 static void ff_layout_free_mirror(struct nfs4_ff_layout_mirror *mirror)
 228 {
 229         struct rpc_cred *cred;
 230
 231         ff_layout_remove_mirror(mirror);
 232         kfree(mirror->fh_versions);
 233         cred = rcu_access_pointer(mirror->ro_cred);
 234         if (cred)
 235                 put_rpccred(cred);
 236         cred = rcu_access_pointer(mirror->rw_cred);
 237         if (cred)
 238                 put_rpccred(cred);
 239         nfs4_ff_layout_put_deviceid(mirror->mirror_ds);
 240         kfree(mirror);
 241 }
 242
 243 static void ff_layout_put_mirror(struct nfs4_ff_layout_mirror *mirror)
 244 {
 245         if (mirror != NULL && atomic_dec_and_test(&mirror->ref))
 246                 ff_layout_free_mirror(mirror);
 247 }
 248
 249 static void ff_layout_free_mirror_array(struct nfs4_ff_layout_segment *fls)
 250 {
 251         int i;
 252
 253         if (fls->mirror_array) {
 254                 for (i = 0; i < fls->mirror_array_cnt; i++) {
 255                         /* normally mirror_ds is freed in
 256                          * .free_deviceid_node but we still do it here
 257                          * for .alloc_lseg error path */
 258                         ff_layout_put_mirror(fls->mirror_array[i]);
 259                 }
 260                 kfree(fls->mirror_array);
 261                 fls->mirror_array = NULL;
 262         }
 263 }
 264
 265 static int ff_layout_check_layout(struct nfs4_layoutget_res *lgr)
 266 {
 267         int ret = 0;
 268
 269         dprintk("--> %s\n", __func__);
 270
 271         /* FIXME: remove this check when layout segment support is added */
 272         if (lgr->range.offset != 0 ||
 273             lgr->range.length != NFS4_MAX_UINT64) {
 274                 dprintk("%s Only whole file layouts supported. Use MDS i/o\n",
 275                         __func__);
 276                 ret = -EINVAL;
 277         }
 278
 279         dprintk("--> %s returns %d\n", __func__, ret);
 280         return ret;
 281 }
 282
 283 static void _ff_layout_free_lseg(struct nfs4_ff_layout_segment *fls)
 284 {
 285         if (fls) {
 286                 ff_layout_free_mirror_array(fls);
 287                 kfree(fls);
 288         }
 289 }
 290
 291 static bool
 292 ff_lseg_range_is_after(const struct pnfs_layout_range *l1,
 293                 const struct pnfs_layout_range *l2)
 294 {
 295         u64 end1, end2;
 296
 297         if (l1->iomode != l2->iomode)
 298                 return l1->iomode != IOMODE_READ;
 299         end1 = pnfs_calc_offset_end(l1->offset, l1->length);
 300         end2 = pnfs_calc_offset_end(l2->offset, l2->length);
 301         if (end1 < l2->offset)
 302                 return false;
 303         if (end2 < l1->offset)
 304                 return true;
 305         return l2->offset <= l1->offset;
 306 }
 307
 308 static bool
 309 ff_lseg_merge(struct pnfs_layout_segment *new,
 310                 struct pnfs_layout_segment *old)
 311 {
 312         u64 new_end, old_end;
 313
 314         if (test_bit(NFS_LSEG_LAYOUTRETURN, &old->pls_flags))
 315                 return false;
 316         if (new->pls_range.iomode != old->pls_range.iomode)
 317                 return false;
 318         old_end = pnfs_calc_offset_end(old->pls_range.offset,
 319                         old->pls_range.length);
 320         if (old_end < new->pls_range.offset)
 321                 return false;
 322         new_end = pnfs_calc_offset_end(new->pls_range.offset,
 323                         new->pls_range.length);
 324         if (new_end < old->pls_range.offset)
 325                 return false;
 326
 327         /* Mergeable: copy info from 'old' to 'new' */
 328         if (new_end < old_end)
 329                 new_end = old_end;
 330         if (new->pls_range.offset < old->pls_range.offset)
 331                 new->pls_range.offset = old->pls_range.offset;
 332         new->pls_range.length = pnfs_calc_offset_length(new->pls_range.offset,
 333                         new_end);
 334         if (test_bit(NFS_LSEG_ROC, &old->pls_flags))
 335                 set_bit(NFS_LSEG_ROC, &new->pls_flags);
 336         return true;
 337 }
 338
 339 static void
 340 ff_layout_add_lseg(struct pnfs_layout_hdr *lo,
 341                 struct pnfs_layout_segment *lseg,
 342                 struct list_head *free_me)
 343 {
 344         pnfs_generic_layout_insert_lseg(lo, lseg,
 345                         ff_lseg_range_is_after,
 346                         ff_lseg_merge,
 347                         free_me);
 348 }
 349
 350 static void ff_layout_sort_mirrors(struct nfs4_ff_layout_segment *fls)
 351 {
 352         int i, j;
 353
 354         for (i = 0; i < fls->mirror_array_cnt - 1; i++) {
 355                 for (j = i + 1; j < fls->mirror_array_cnt; j++)
 356                         if (fls->mirror_array[i]->efficiency <
 357                             fls->mirror_array[j]->efficiency)
 358                                 swap(fls->mirror_array[i],
 359                                      fls->mirror_array[j]);
 360         }
 361 }
 362
 363 static struct pnfs_layout_segment *
 364 ff_layout_alloc_lseg(struct pnfs_layout_hdr *lh,
 365                      struct nfs4_layoutget_res *lgr,
 366                      gfp_t gfp_flags)
 367 {
 368         struct pnfs_layout_segment *ret;
 369         struct nfs4_ff_layout_segment *fls = NULL;
 370         struct xdr_stream stream;
 371         struct xdr_buf buf;
 372         struct page *scratch;
 373         u64 stripe_unit;
 374         u32 mirror_array_cnt;
 375         __be32 *p;
 376         int i, rc;
 377
 378         dprintk("--> %s\n", __func__);
 379         scratch = alloc_page(gfp_flags);
 380         if (!scratch)
 381                 return ERR_PTR(-ENOMEM);
 382
 383         xdr_init_decode_pages(&stream, &buf, lgr->layoutp->pages,
 384                               lgr->layoutp->len);
 385         xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
 386
 387         /* stripe unit and mirror_array_cnt */
 388         rc = -EIO;
 389         p = xdr_inline_decode(&stream, 8 + 4);
 390         if (!p)
 391                 goto out_err_free;
 392
 393         p = xdr_decode_hyper(p, &stripe_unit);
 394         mirror_array_cnt = be32_to_cpup(p++);
 395         dprintk("%s: stripe_unit=%llu mirror_array_cnt=%u\n", __func__,
 396                 stripe_unit, mirror_array_cnt);
 397
 398         if (mirror_array_cnt > NFS4_FLEXFILE_LAYOUT_MAX_MIRROR_CNT ||
 399             mirror_array_cnt == 0)
 400                 goto out_err_free;
 401
 402         rc = -ENOMEM;
 403         fls = kzalloc(sizeof(*fls), gfp_flags);
 404         if (!fls)
 405                 goto out_err_free;
 406
 407         fls->mirror_array_cnt = mirror_array_cnt;
 408         fls->stripe_unit = stripe_unit;
 409         fls->mirror_array = kcalloc(fls->mirror_array_cnt,
 410                                     sizeof(fls->mirror_array[0]), gfp_flags);
 411         if (fls->mirror_array == NULL)
 412                 goto out_err_free;
 413
 414         for (i = 0; i < fls->mirror_array_cnt; i++) {
 415                 struct nfs4_ff_layout_mirror *mirror;
 416                 struct auth_cred acred = { .group_info = ff_zero_group };
 417                 struct rpc_cred __rcu *cred;
 418                 u32 ds_count, fh_count, id;
 419                 int j;
 420
 421                 rc = -EIO;
 422                 p = xdr_inline_decode(&stream, 4);
 423                 if (!p)
 424                         goto out_err_free;
 425                 ds_count = be32_to_cpup(p);
 426
 427                 /* FIXME: allow for striping? */
 428                 if (ds_count != 1)
 429                         goto out_err_free;
 430
 431                 fls->mirror_array[i] = ff_layout_alloc_mirror(gfp_flags);
 432                 if (fls->mirror_array[i] == NULL) {
 433                         rc = -ENOMEM;
 434                         goto out_err_free;
 435                 }
 436
 437                 fls->mirror_array[i]->ds_count = ds_count;
 438
 439                 /* deviceid */
 440                 rc = decode_deviceid(&stream, &fls->mirror_array[i]->devid);
 441                 if (rc)
 442                         goto out_err_free;
 443
 444                 /* efficiency */
 445                 rc = -EIO;
 446                 p = xdr_inline_decode(&stream, 4);
 447                 if (!p)
 448                         goto out_err_free;
 449                 fls->mirror_array[i]->efficiency = be32_to_cpup(p);
 450
 451                 /* stateid */
 452                 rc = decode_pnfs_stateid(&stream, &fls->mirror_array[i]->stateid);
 453                 if (rc)
 454                         goto out_err_free;
 455
 456                 /* fh */
 457                 p = xdr_inline_decode(&stream, 4);
 458                 if (!p)
 459                         goto out_err_free;
 460                 fh_count = be32_to_cpup(p);
 461
 462                 fls->mirror_array[i]->fh_versions =
 463                         kzalloc(fh_count * sizeof(struct nfs_fh),
 464                                 gfp_flags);
 465                 if (fls->mirror_array[i]->fh_versions == NULL) {
 466                         rc = -ENOMEM;
 467                         goto out_err_free;
 468                 }
 469
 470                 for (j = 0; j < fh_count; j++) {
 471                         rc = decode_nfs_fh(&stream,
 472                                            &fls->mirror_array[i]->fh_versions[j]);
 473                         if (rc)
 474                                 goto out_err_free;
 475                 }
 476
 477                 fls->mirror_array[i]->fh_versions_cnt = fh_count;
 478
 479                 /* user */
 480                 rc = decode_name(&stream, &id);
 481                 if (rc)
 482                         goto out_err_free;
 483
 484                 acred.uid = make_kuid(&init_user_ns, id);
 485
 486                 /* group */
 487                 rc = decode_name(&stream, &id);
 488                 if (rc)
 489                         goto out_err_free;
 490
 491                 acred.gid = make_kgid(&init_user_ns, id);
 492
 493                 /* find the cred for it */
 494                 rcu_assign_pointer(cred, rpc_lookup_generic_cred(&acred, 0, gfp_flags));
 495                 if (IS_ERR(cred)) {
 496                         rc = PTR_ERR(cred);
 497                         goto out_err_free;
 498                 }
 499
 500                 if (lgr->range.iomode == IOMODE_READ)
 501                         rcu_assign_pointer(fls->mirror_array[i]->ro_cred, cred);
 502                 else
 503                         rcu_assign_pointer(fls->mirror_array[i]->rw_cred, cred);
 504
 505                 mirror = ff_layout_add_mirror(lh, fls->mirror_array[i]);
 506                 if (mirror != fls->mirror_array[i]) {
 507                         /* swap cred ptrs so free_mirror will clean up old */
 508                         if (lgr->range.iomode == IOMODE_READ) {
 509                                 cred = xchg(&mirror->ro_cred, cred);
 510                                 rcu_assign_pointer(fls->mirror_array[i]->ro_cred, cred);
 511                         } else {
 512                                 cred = xchg(&mirror->rw_cred, cred);
 513                                 rcu_assign_pointer(fls->mirror_array[i]->rw_cred, cred);
 514                         }
 515                         ff_layout_free_mirror(fls->mirror_array[i]);
 516                         fls->mirror_array[i] = mirror;
 517                 }
 518
 519                 dprintk("%s: iomode %s uid %u gid %u\n", __func__,
 520                         lgr->range.iomode == IOMODE_READ ? "READ" : "RW",
 521                         from_kuid(&init_user_ns, acred.uid),
 522                         from_kgid(&init_user_ns, acred.gid));
 523         }
 524
 525         p = xdr_inline_decode(&stream, 4);
 526         if (!p)
 527                 goto out_sort_mirrors;
 528         fls->flags = be32_to_cpup(p);
 529
 530         p = xdr_inline_decode(&stream, 4);
 531         if (!p)
 532                 goto out_sort_mirrors;
 533         for (i=0; i < fls->mirror_array_cnt; i++)
 534                 fls->mirror_array[i]->report_interval = be32_to_cpup(p);
 535
 536 out_sort_mirrors:
 537         ff_layout_sort_mirrors(fls);
 538         rc = ff_layout_check_layout(lgr);
 539         if (rc)
 540                 goto out_err_free;
 541         ret = &fls->generic_hdr;
 542         dprintk("<-- %s (success)\n", __func__);
 543 out_free_page:
 544         __free_page(scratch);
 545         return ret;
 546 out_err_free:
 547         _ff_layout_free_lseg(fls);
 548         ret = ERR_PTR(rc);
 549         dprintk("<-- %s (%d)\n", __func__, rc);
 550         goto out_free_page;
 551 }
 552
 553 static bool ff_layout_has_rw_segments(struct pnfs_layout_hdr *layout)
 554 {
 555         struct pnfs_layout_segment *lseg;
 556
 557         list_for_each_entry(lseg, &layout->plh_segs, pls_list)
 558                 if (lseg->pls_range.iomode == IOMODE_RW)
 559                         return true;
 560
 561         return false;
 562 }
 563
 564 static void
 565 ff_layout_free_lseg(struct pnfs_layout_segment *lseg)
 566 {
 567         struct nfs4_ff_layout_segment *fls = FF_LAYOUT_LSEG(lseg);
 568
 569         dprintk("--> %s\n", __func__);
 570
 571         if (lseg->pls_range.iomode == IOMODE_RW) {
 572                 struct nfs4_flexfile_layout *ffl;
 573                 struct inode *inode;
 574
 575                 ffl = FF_LAYOUT_FROM_HDR(lseg->pls_layout);
 576                 inode = ffl->generic_hdr.plh_inode;
 577                 spin_lock(&inode->i_lock);
 578                 if (!ff_layout_has_rw_segments(lseg->pls_layout)) {
 579                         ffl->commit_info.nbuckets = 0;
 580                         kfree(ffl->commit_info.buckets);
 581                         ffl->commit_info.buckets = NULL;
 582                 }
 583                 spin_unlock(&inode->i_lock);
 584         }
 585         _ff_layout_free_lseg(fls);
 586 }
 587
 588 /* Return 1 until we have multiple lsegs support */
 589 static int
 590 ff_layout_get_lseg_count(struct nfs4_ff_layout_segment *fls)
 591 {
 592         return 1;
 593 }
 594
 595 static void
 596 nfs4_ff_start_busy_timer(struct nfs4_ff_busy_timer *timer, ktime_t now)
 597 {
 598         /* first IO request? */
 599         if (atomic_inc_return(&timer->n_ops) == 1) {
 600                 timer->start_time = now;
 601         }
 602 }
 603
 604 static ktime_t
 605 nfs4_ff_end_busy_timer(struct nfs4_ff_busy_timer *timer, ktime_t now)
 606 {
 607         ktime_t start;
 608
 609         if (atomic_dec_return(&timer->n_ops) < 0)
 610                 WARN_ON_ONCE(1);
 611
 612         start = timer->start_time;
 613         timer->start_time = now;
 614         return ktime_sub(now, start);
 615 }
 616
 617 static bool
 618 nfs4_ff_layoutstat_start_io(struct nfs4_ff_layout_mirror *mirror,
 619                             struct nfs4_ff_layoutstat *layoutstat,
 620                             ktime_t now)
 621 {
 622         s64 report_interval = FF_LAYOUTSTATS_REPORT_INTERVAL;
 623         struct nfs4_flexfile_layout *ffl = FF_LAYOUT_FROM_HDR(mirror->layout);
 624
 625         nfs4_ff_start_busy_timer(&layoutstat->busy_timer, now);
 626         if (ktime_equal(mirror->start_time, 0))
 627                 mirror->start_time = now;
 628         if (mirror->report_interval != 0)
 629                 report_interval = (s64)mirror->report_interval * 1000LL;
 630         else if (layoutstats_timer != 0)
 631                 report_interval = (s64)layoutstats_timer * 1000LL;
 632         if (ktime_to_ms(ktime_sub(now, ffl->last_report_time)) >=
 633                         report_interval) {
 634                 ffl->last_report_time = now;
 635                 return true;
 636         }
 637
 638         return false;
 639 }
 640
 641 static void
 642 nfs4_ff_layout_stat_io_update_requested(struct nfs4_ff_layoutstat *layoutstat,
 643                 __u64 requested)
 644 {
 645         struct nfs4_ff_io_stat *iostat = &layoutstat->io_stat;
 646
 647         iostat->ops_requested++;
 648         iostat->bytes_requested += requested;
 649 }
 650
 651 static void
 652 nfs4_ff_layout_stat_io_update_completed(struct nfs4_ff_layoutstat *layoutstat,
 653                 __u64 requested,
 654                 __u64 completed,
 655                 ktime_t time_completed,
 656                 ktime_t time_started)
 657 {
 658         struct nfs4_ff_io_stat *iostat = &layoutstat->io_stat;
 659         ktime_t completion_time = ktime_sub(time_completed, time_started);
 660         ktime_t timer;
 661
 662         iostat->ops_completed++;
 663         iostat->bytes_completed += completed;
 664         iostat->bytes_not_delivered += requested - completed;
 665
 666         timer = nfs4_ff_end_busy_timer(&layoutstat->busy_timer, time_completed);
 667         iostat->total_busy_time =
 668                         ktime_add(iostat->total_busy_time, timer);
 669         iostat->aggregate_completion_time =
 670                         ktime_add(iostat->aggregate_completion_time,
 671                                         completion_time);
 672 }
 673
 674 static void
 675 nfs4_ff_layout_stat_io_start_read(struct inode *inode,
 676                 struct nfs4_ff_layout_mirror *mirror,
 677                 __u64 requested, ktime_t now)
 678 {
 679         bool report;
 680
 681         spin_lock(&mirror->lock);
 682         report = nfs4_ff_layoutstat_start_io(mirror, &mirror->read_stat, now);
 683         nfs4_ff_layout_stat_io_update_requested(&mirror->read_stat, requested);
 684         set_bit(NFS4_FF_MIRROR_STAT_AVAIL, &mirror->flags);
 685         spin_unlock(&mirror->lock);
 686
 687         if (report)
 688                 pnfs_report_layoutstat(inode, GFP_KERNEL);
 689 }
 690
 691 static void
 692 nfs4_ff_layout_stat_io_end_read(struct rpc_task *task,
 693                 struct nfs4_ff_layout_mirror *mirror,
 694                 __u64 requested,
 695                 __u64 completed)
 696 {
 697         spin_lock(&mirror->lock);
 698         nfs4_ff_layout_stat_io_update_completed(&mirror->read_stat,
 699                         requested, completed,
 700                         ktime_get(), task->tk_start);
 701         set_bit(NFS4_FF_MIRROR_STAT_AVAIL, &mirror->flags);
 702         spin_unlock(&mirror->lock);
 703 }
 704
 705 static void
 706 nfs4_ff_layout_stat_io_start_write(struct inode *inode,
 707                 struct nfs4_ff_layout_mirror *mirror,
 708                 __u64 requested, ktime_t now)
 709 {
 710         bool report;
 711
 712         spin_lock(&mirror->lock);
 713         report = nfs4_ff_layoutstat_start_io(mirror , &mirror->write_stat, now);
 714         nfs4_ff_layout_stat_io_update_requested(&mirror->write_stat, requested);
 715         set_bit(NFS4_FF_MIRROR_STAT_AVAIL, &mirror->flags);
 716         spin_unlock(&mirror->lock);
 717
 718         if (report)
 719                 pnfs_report_layoutstat(inode, GFP_NOIO);
 720 }
 721
 722 static void
 723 nfs4_ff_layout_stat_io_end_write(struct rpc_task *task,
 724                 struct nfs4_ff_layout_mirror *mirror,
 725                 __u64 requested,
 726                 __u64 completed,
 727                 enum nfs3_stable_how committed)
 728 {
 729         if (committed == NFS_UNSTABLE)
 730                 requested = completed = 0;
 731
 732         spin_lock(&mirror->lock);
 733         nfs4_ff_layout_stat_io_update_completed(&mirror->write_stat,
 734                         requested, completed, ktime_get(), task->tk_start);
 735         set_bit(NFS4_FF_MIRROR_STAT_AVAIL, &mirror->flags);
 736         spin_unlock(&mirror->lock);
 737 }
 738
 739 static int
 740 ff_layout_alloc_commit_info(struct pnfs_layout_segment *lseg,
 741                             struct nfs_commit_info *cinfo,
 742                             gfp_t gfp_flags)
 743 {
 744         struct nfs4_ff_layout_segment *fls = FF_LAYOUT_LSEG(lseg);
 745         struct pnfs_commit_bucket *buckets;
 746         int size;
 747
 748         if (cinfo->ds->nbuckets != 0) {
 749                 /* This assumes there is only one RW lseg per file.
 750                  * To support multiple lseg per file, we need to
 751                  * change struct pnfs_commit_bucket to allow dynamic
 752                  * increasing nbuckets.
 753                  */
 754                 return 0;
 755         }
 756
 757         size = ff_layout_get_lseg_count(fls) * FF_LAYOUT_MIRROR_COUNT(lseg);
 758
 759         buckets = kcalloc(size, sizeof(struct pnfs_commit_bucket),
 760                           gfp_flags);
 761         if (!buckets)
 762                 return -ENOMEM;
 763         else {
 764                 int i;
 765
 766                 spin_lock(&cinfo->inode->i_lock);
 767                 if (cinfo->ds->nbuckets != 0)
 768                         kfree(buckets);
 769                 else {
 770                         cinfo->ds->buckets = buckets;
 771                         cinfo->ds->nbuckets = size;
 772                         for (i = 0; i < size; i++) {
 773                                 INIT_LIST_HEAD(&buckets[i].written);
 774                                 INIT_LIST_HEAD(&buckets[i].committing);
 775                                 /* mark direct verifier as unset */
 776                                 buckets[i].direct_verf.committed =
 777                                         NFS_INVALID_STABLE_HOW;
 778                         }
 779                 }
 780                 spin_unlock(&cinfo->inode->i_lock);
 781                 return 0;
 782         }
 783 }
 784
 785 static struct nfs4_pnfs_ds *
 786 ff_layout_choose_best_ds_for_read(struct pnfs_layout_segment *lseg,
 787                                   int start_idx,
 788                                   int *best_idx)
 789 {
 790         struct nfs4_ff_layout_segment *fls = FF_LAYOUT_LSEG(lseg);
 791         struct nfs4_pnfs_ds *ds;
 792         bool fail_return = false;
 793         int idx;
 794
 795         /* mirrors are sorted by efficiency */
 796         for (idx = start_idx; idx < fls->mirror_array_cnt; idx++) {
 797                 if (idx+1 == fls->mirror_array_cnt)
 798                         fail_return = true;
 799                 ds = nfs4_ff_layout_prepare_ds(lseg, idx, fail_return);
 800                 if (ds) {
 801                         *best_idx = idx;
 802                         return ds;
 803                 }
 804         }
 805
 806         return NULL;
 807 }
 808
 809 static void
 810 ff_layout_pg_get_read(struct nfs_pageio_descriptor *pgio,
 811                       struct nfs_page *req,
 812                       bool strict_iomode)
 813 {
 814 retry_strict:
 815         pnfs_put_lseg(pgio->pg_lseg);
 816         pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
 817                                            req->wb_context,
 818                                            0,
 819                                            NFS4_MAX_UINT64,
 820                                            IOMODE_READ,
 821                                            strict_iomode,
 822                                            GFP_KERNEL);
 823         if (IS_ERR(pgio->pg_lseg)) {
 824                 pgio->pg_error = PTR_ERR(pgio->pg_lseg);
 825                 pgio->pg_lseg = NULL;
 826         }
 827
 828         /* If we don't have checking, do get a IOMODE_RW
 829          * segment, and the server wants to avoid READs
 830          * there, then retry!
 831          */
 832         if (pgio->pg_lseg && !strict_iomode &&
 833             ff_layout_avoid_read_on_rw(pgio->pg_lseg)) {
 834                 strict_iomode = true;
 835                 goto retry_strict;
 836         }
 837 }
 838
 839 static void
 840 ff_layout_pg_init_read(struct nfs_pageio_descriptor *pgio,
 841                         struct nfs_page *req)
 842 {
 843         struct nfs_pgio_mirror *pgm;
 844         struct nfs4_ff_layout_mirror *mirror;
 845         struct nfs4_pnfs_ds *ds;
 846         int ds_idx;
 847
 848 retry:
 849         /* Use full layout for now */
 850         if (!pgio->pg_lseg)
 851                 ff_layout_pg_get_read(pgio, req, false);
 852         else if (ff_layout_avoid_read_on_rw(pgio->pg_lseg))
 853                 ff_layout_pg_get_read(pgio, req, true);
 854
 855         /* If no lseg, fall back to read through mds */
 856         if (pgio->pg_lseg == NULL)
 857                 goto out_mds;
 858
 859         ds = ff_layout_choose_best_ds_for_read(pgio->pg_lseg, 0, &ds_idx);
 860         if (!ds) {
 861                 if (!ff_layout_no_fallback_to_mds(pgio->pg_lseg))
 862                         goto out_mds;
 863                 pnfs_put_lseg(pgio->pg_lseg);
 864                 pgio->pg_lseg = NULL;
 865                 /* Sleep for 1 second before retrying */
 866                 ssleep(1);
 867                 goto retry;
 868         }
 869
 870         mirror = FF_LAYOUT_COMP(pgio->pg_lseg, ds_idx);
 871
 872         pgio->pg_mirror_idx = ds_idx;
 873
 874         /* read always uses only one mirror - idx 0 for pgio layer */
 875         pgm = &pgio->pg_mirrors[0];
 876         pgm->pg_bsize = mirror->mirror_ds->ds_versions[0].rsize;
 877
 878         return;
 879 out_mds:
 880         pnfs_put_lseg(pgio->pg_lseg);
 881         pgio->pg_lseg = NULL;
 882         nfs_pageio_reset_read_mds(pgio);
 883 }
 884
 885 static void
 886 ff_layout_pg_init_write(struct nfs_pageio_descriptor *pgio,
 887                         struct nfs_page *req)
 888 {
 889         struct nfs4_ff_layout_mirror *mirror;
 890         struct nfs_pgio_mirror *pgm;
 891         struct nfs_commit_info cinfo;
 892         struct nfs4_pnfs_ds *ds;
 893         int i;
 894         int status;
 895
 896 retry:
 897         if (!pgio->pg_lseg) {
 898                 pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
 899                                                    req->wb_context,
 900                                                    0,
 901                                                    NFS4_MAX_UINT64,
 902                                                    IOMODE_RW,
 903                                                    false,
 904                                                    GFP_NOFS);
 905                 if (IS_ERR(pgio->pg_lseg)) {
 906                         pgio->pg_error = PTR_ERR(pgio->pg_lseg);
 907                         pgio->pg_lseg = NULL;
 908                         return;
 909                 }
 910         }
 911         /* If no lseg, fall back to write through mds */
 912         if (pgio->pg_lseg == NULL)
 913                 goto out_mds;
 914
 915         nfs_init_cinfo(&cinfo, pgio->pg_inode, pgio->pg_dreq);
 916         status = ff_layout_alloc_commit_info(pgio->pg_lseg, &cinfo, GFP_NOFS);
 917         if (status < 0)
 918                 goto out_mds;
 919
 920         /* Use a direct mapping of ds_idx to pgio mirror_idx */
 921         if (WARN_ON_ONCE(pgio->pg_mirror_count !=
 922             FF_LAYOUT_MIRROR_COUNT(pgio->pg_lseg)))
 923                 goto out_mds;
 924
 925         for (i = 0; i < pgio->pg_mirror_count; i++) {
 926                 ds = nfs4_ff_layout_prepare_ds(pgio->pg_lseg, i, true);
 927                 if (!ds) {
 928                         if (!ff_layout_no_fallback_to_mds(pgio->pg_lseg))
 929                                 goto out_mds;
 930                         pnfs_put_lseg(pgio->pg_lseg);
 931                         pgio->pg_lseg = NULL;
 932                         /* Sleep for 1 second before retrying */
 933                         ssleep(1);
 934                         goto retry;
 935                 }
 936                 pgm = &pgio->pg_mirrors[i];
 937                 mirror = FF_LAYOUT_COMP(pgio->pg_lseg, i);
 938                 pgm->pg_bsize = mirror->mirror_ds->ds_versions[0].wsize;
 939         }
 940
 941         return;
 942
 943 out_mds:
 944         pnfs_put_lseg(pgio->pg_lseg);
 945         pgio->pg_lseg = NULL;
 946         nfs_pageio_reset_write_mds(pgio);
 947 }
 948
 949 static unsigned int
 950 ff_layout_pg_get_mirror_count_write(struct nfs_pageio_descriptor *pgio,
 951                                     struct nfs_page *req)
 952 {
 953         if (!pgio->pg_lseg) {
 954                 pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
 955                                                    req->wb_context,
 956                                                    0,
 957                                                    NFS4_MAX_UINT64,
 958                                                    IOMODE_RW,
 959                                                    false,
 960                                                    GFP_NOFS);
 961                 if (IS_ERR(pgio->pg_lseg)) {
 962                         pgio->pg_error = PTR_ERR(pgio->pg_lseg);
 963                         pgio->pg_lseg = NULL;
 964                         goto out;
 965                 }
 966         }
 967         if (pgio->pg_lseg)
 968                 return FF_LAYOUT_MIRROR_COUNT(pgio->pg_lseg);
 969
 970         /* no lseg means that pnfs is not in use, so no mirroring here */
 971         nfs_pageio_reset_write_mds(pgio);
 972 out:
 973         return 1;
 974 }
 975
 976 static const struct nfs_pageio_ops ff_layout_pg_read_ops = {
 977         .pg_init = ff_layout_pg_init_read,
 978         .pg_test = pnfs_generic_pg_test,
 979         .pg_doio = pnfs_generic_pg_readpages,
 980         .pg_cleanup = pnfs_generic_pg_cleanup,
 981 };
 982
 983 static const struct nfs_pageio_ops ff_layout_pg_write_ops = {
 984         .pg_init = ff_layout_pg_init_write,
 985         .pg_test = pnfs_generic_pg_test,
 986         .pg_doio = pnfs_generic_pg_writepages,
 987         .pg_get_mirror_count = ff_layout_pg_get_mirror_count_write,
 988         .pg_cleanup = pnfs_generic_pg_cleanup,
 989 };
 990
 991 static void ff_layout_reset_write(struct nfs_pgio_header *hdr, bool retry_pnfs)
 992 {
 993         struct rpc_task *task = &hdr->task;
 994
 995         pnfs_layoutcommit_inode(hdr->inode, false);
 996
 997         if (retry_pnfs) {
 998                 dprintk("%s Reset task %5u for i/o through pNFS "
 999                         "(req %s/%llu, %u bytes @ offset %llu)\n", __func__,
1000                         hdr->task.tk_pid,
1001                         hdr->inode->i_sb->s_id,
1002                         (unsigned long long)NFS_FILEID(hdr->inode),
1003                         hdr->args.count,
1004                         (unsigned long long)hdr->args.offset);
1005
1006                 hdr->completion_ops->reschedule_io(hdr);
1007                 return;
1008         }
1009
1010         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
1011                 dprintk("%s Reset task %5u for i/o through MDS "
1012                         "(req %s/%llu, %u bytes @ offset %llu)\n", __func__,
1013                         hdr->task.tk_pid,
1014                         hdr->inode->i_sb->s_id,
1015                         (unsigned long long)NFS_FILEID(hdr->inode),
1016                         hdr->args.count,
1017                         (unsigned long long)hdr->args.offset);
1018
1019                 task->tk_status = pnfs_write_done_resend_to_mds(hdr);
1020         }
1021 }
1022
1023 static void ff_layout_reset_read(struct nfs_pgio_header *hdr)
1024 {
1025         struct rpc_task *task = &hdr->task;
1026
1027         pnfs_layoutcommit_inode(hdr->inode, false);
1028
1029         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
1030                 dprintk("%s Reset task %5u for i/o through MDS "
1031                         "(req %s/%llu, %u bytes @ offset %llu)\n", __func__,
1032                         hdr->task.tk_pid,
1033                         hdr->inode->i_sb->s_id,
1034                         (unsigned long long)NFS_FILEID(hdr->inode),
1035                         hdr->args.count,
1036                         (unsigned long long)hdr->args.offset);
1037
1038                 task->tk_status = pnfs_read_done_resend_to_mds(hdr);
1039         }
1040 }
1041
1042 static int ff_layout_async_handle_error_v4(struct rpc_task *task,
1043                                            struct nfs4_state *state,
1044                                            struct nfs_client *clp,
1045                                            struct pnfs_layout_segment *lseg,
1046                                            int idx)
1047 {
1048         struct pnfs_layout_hdr *lo = lseg->pls_layout;
1049         struct inode *inode = lo->plh_inode;
1050         struct nfs_server *mds_server = NFS_SERVER(inode);
1051
1052         struct nfs4_deviceid_node *devid = FF_LAYOUT_DEVID_NODE(lseg, idx);
1053         struct nfs_client *mds_client = mds_server->nfs_client;
1054         struct nfs4_slot_table *tbl = &clp->cl_session->fc_slot_table;
1055
1056         if (task->tk_status >= 0)
1057                 return 0;
1058
1059         switch (task->tk_status) {
1060         /* MDS state errors */
1061         case -NFS4ERR_DELEG_REVOKED:
1062         case -NFS4ERR_ADMIN_REVOKED:
1063         case -NFS4ERR_BAD_STATEID:
1064                 if (state == NULL)
1065                         break;
1066                 nfs_remove_bad_delegation(state->inode, NULL);
1067         case -NFS4ERR_OPENMODE:
1068                 if (state == NULL)
1069                         break;
1070                 if (nfs4_schedule_stateid_recovery(mds_server, state) < 0)
1071                         goto out_bad_stateid;
1072                 goto wait_on_recovery;
1073         case -NFS4ERR_EXPIRED:
1074                 if (state != NULL) {
1075                         if (nfs4_schedule_stateid_recovery(mds_server, state) < 0)
1076                                 goto out_bad_stateid;
1077                 }
1078                 nfs4_schedule_lease_recovery(mds_client);
1079                 goto wait_on_recovery;
1080         /* DS session errors */
1081         case -NFS4ERR_BADSESSION:
1082         case -NFS4ERR_BADSLOT:
1083         case -NFS4ERR_BAD_HIGH_SLOT:
1084         case -NFS4ERR_DEADSESSION:
1085         case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1086         case -NFS4ERR_SEQ_FALSE_RETRY:
1087         case -NFS4ERR_SEQ_MISORDERED:
1088                 dprintk("%s ERROR %d, Reset session. Exchangeid "
1089                         "flags 0x%x\n", __func__, task->tk_status,
1090                         clp->cl_exchange_flags);
1091                 nfs4_schedule_session_recovery(clp->cl_session, task->tk_status);
1092                 break;
1093         case -NFS4ERR_DELAY:
1094         case -NFS4ERR_GRACE:
1095                 rpc_delay(task, FF_LAYOUT_POLL_RETRY_MAX);
1096                 break;
1097         case -NFS4ERR_RETRY_UNCACHED_REP:
1098                 break;
1099         /* Invalidate Layout errors */
1100         case -NFS4ERR_PNFS_NO_LAYOUT:
1101         case -ESTALE:           /* mapped NFS4ERR_STALE */
1102         case -EBADHANDLE:       /* mapped NFS4ERR_BADHANDLE */
1103         case -EISDIR:           /* mapped NFS4ERR_ISDIR */
1104         case -NFS4ERR_FHEXPIRED:
1105         case -NFS4ERR_WRONG_TYPE:
1106                 dprintk("%s Invalid layout error %d\n", __func__,
1107                         task->tk_status);
1108                 /*
1109                  * Destroy layout so new i/o will get a new layout.
1110                  * Layout will not be destroyed until all current lseg
1111                  * references are put. Mark layout as invalid to resend failed
1112                  * i/o and all i/o waiting on the slot table to the MDS until
1113                  * layout is destroyed and a new valid layout is obtained.
1114                  */
1115                 pnfs_destroy_layout(NFS_I(inode));
1116                 rpc_wake_up(&tbl->slot_tbl_waitq);
1117                 goto reset;
1118         /* RPC connection errors */
1119         case -ECONNREFUSED:
1120         case -EHOSTDOWN:
1121         case -EHOSTUNREACH:
1122         case -ENETUNREACH:
1123         case -EIO:
1124         case -ETIMEDOUT:
1125         case -EPIPE:
1126                 dprintk("%s DS connection error %d\n", __func__,
1127                         task->tk_status);
1128                 nfs4_delete_deviceid(devid->ld, devid->nfs_client,
1129                                 &devid->deviceid);
1130                 rpc_wake_up(&tbl->slot_tbl_waitq);
1131                 /* fall through */
1132         default:
1133                 if (ff_layout_avoid_mds_available_ds(lseg))
1134                         return -NFS4ERR_RESET_TO_PNFS;
1135 reset:
1136                 dprintk("%s Retry through MDS. Error %d\n", __func__,
1137                         task->tk_status);
1138                 return -NFS4ERR_RESET_TO_MDS;
1139         }
1140 out:
1141         task->tk_status = 0;
1142         return -EAGAIN;
1143 out_bad_stateid:
1144         task->tk_status = -EIO;
1145         return 0;
1146 wait_on_recovery:
1147         rpc_sleep_on(&mds_client->cl_rpcwaitq, task, NULL);
1148         if (test_bit(NFS4CLNT_MANAGER_RUNNING, &mds_client->cl_state) == 0)
1149                 rpc_wake_up_queued_task(&mds_client->cl_rpcwaitq, task);
1150         goto out;
1151 }
1152
1153 /* Retry all errors through either pNFS or MDS except for -EJUKEBOX */
1154 static int ff_layout_async_handle_error_v3(struct rpc_task *task,
1155                                            struct pnfs_layout_segment *lseg,
1156                                            int idx)
1157 {
1158         struct nfs4_deviceid_node *devid = FF_LAYOUT_DEVID_NODE(lseg, idx);
1159
1160         if (task->tk_status >= 0)
1161                 return 0;
1162
1163         switch (task->tk_status) {
1164         /* File access problems. Don't mark the device as unavailable */
1165         case -EACCES:
1166         case -ESTALE:
1167         case -EISDIR:
1168         case -EBADHANDLE:
1169         case -ELOOP:
1170         case -ENOSPC:
1171                 break;
1172         case -EJUKEBOX:
1173                 nfs_inc_stats(lseg->pls_layout->plh_inode, NFSIOS_DELAY);
1174                 goto out_retry;
1175         default:
1176                 dprintk("%s DS connection error %d\n", __func__,
1177                         task->tk_status);
1178                 nfs4_delete_deviceid(devid->ld, devid->nfs_client,
1179                                 &devid->deviceid);
1180         }
1181         /* FIXME: Need to prevent infinite looping here. */
1182         return -NFS4ERR_RESET_TO_PNFS;
1183 out_retry:
1184         task->tk_status = 0;
1185         rpc_restart_call_prepare(task);
1186         rpc_delay(task, NFS_JUKEBOX_RETRY_TIME);
1187         return -EAGAIN;
1188 }
1189
1190 static int ff_layout_async_handle_error(struct rpc_task *task,
1191                                         struct nfs4_state *state,
1192                                         struct nfs_client *clp,
1193                                         struct pnfs_layout_segment *lseg,
1194                                         int idx)
1195 {
1196         int vers = clp->cl_nfs_mod->rpc_vers->number;
1197
1198         switch (vers) {
1199         case 3:
1200                 return ff_layout_async_handle_error_v3(task, lseg, idx);
1201         case 4:
1202                 return ff_layout_async_handle_error_v4(task, state, clp,
1203                                                        lseg, idx);
1204         default:
1205                 /* should never happen */
1206                 WARN_ON_ONCE(1);
1207                 return 0;
1208         }
1209 }
1210
1211 static void ff_layout_io_track_ds_error(struct pnfs_layout_segment *lseg,
1212                                         int idx, u64 offset, u64 length,
1213                                         u32 status, int opnum, int error)
1214 {
1215         struct nfs4_ff_layout_mirror *mirror;
1216         int err;
1217
1218         if (status == 0) {
1219                 switch (error) {
1220                 case -ETIMEDOUT:
1221                 case -EPFNOSUPPORT:
1222                 case -EPROTONOSUPPORT:
1223                 case -EOPNOTSUPP:
1224                 case -ECONNREFUSED:
1225                 case -ECONNRESET:
1226                 case -EHOSTDOWN:
1227                 case -EHOSTUNREACH:
1228                 case -ENETUNREACH:
1229                 case -EADDRINUSE:
1230                 case -ENOBUFS:
1231                 case -EPIPE:
1232                 case -EPERM:
1233                         status = NFS4ERR_NXIO;
1234                         break;
1235                 case -EACCES:
1236                         status = NFS4ERR_ACCESS;
1237                         break;
1238                 default:
1239                         return;
1240                 }
1241         }
1242
1243         switch (status) {
1244         case NFS4ERR_DELAY:
1245         case NFS4ERR_GRACE:
1246                 return;
1247         default:
1248                 break;
1249         }
1250
1251         mirror = FF_LAYOUT_COMP(lseg, idx);
1252         err = ff_layout_track_ds_error(FF_LAYOUT_FROM_HDR(lseg->pls_layout),
1253                                        mirror, offset, length, status, opnum,
1254                                        GFP_NOIO);
1255         pnfs_error_mark_layout_for_return(lseg->pls_layout->plh_inode, lseg);
1256         dprintk("%s: err %d op %d status %u\n", __func__, err, opnum, status);
1257 }
1258
1259 /* NFS_PROTO call done callback routines */
1260 static int ff_layout_read_done_cb(struct rpc_task *task,
1261                                 struct nfs_pgio_header *hdr)
1262 {
1263         int err;
1264
1265         trace_nfs4_pnfs_read(hdr, task->tk_status);
1266         if (task->tk_status < 0)
1267                 ff_layout_io_track_ds_error(hdr->lseg, hdr->pgio_mirror_idx,
1268                                             hdr->args.offset, hdr->args.count,
1269                                             hdr->res.op_status, OP_READ,
1270                                             task->tk_status);
1271         err = ff_layout_async_handle_error(task, hdr->args.context->state,
1272                                            hdr->ds_clp, hdr->lseg,
1273                                            hdr->pgio_mirror_idx);
1274
1275         switch (err) {
1276         case -NFS4ERR_RESET_TO_PNFS:
1277                 if (ff_layout_choose_best_ds_for_read(hdr->lseg,
1278                                         hdr->pgio_mirror_idx + 1,
1279                                         &hdr->pgio_mirror_idx))
1280                         goto out_eagain;
1281                 ff_layout_read_record_layoutstats_done(task, hdr);
1282                 pnfs_read_resend_pnfs(hdr);
1283                 return task->tk_status;
1284         case -NFS4ERR_RESET_TO_MDS:
1285                 ff_layout_reset_read(hdr);
1286                 return task->tk_status;
1287         case -EAGAIN:
1288                 goto out_eagain;
1289         }
1290
1291         return 0;
1292 out_eagain:
1293         rpc_restart_call_prepare(task);
1294         return -EAGAIN;
1295 }
1296
1297 static bool
1298 ff_layout_need_layoutcommit(struct pnfs_layout_segment *lseg)
1299 {
1300         return !(FF_LAYOUT_LSEG(lseg)->flags & FF_FLAGS_NO_LAYOUTCOMMIT);
1301 }
1302
1303 /*
1304  * We reference the rpc_cred of the first WRITE that triggers the need for
1305  * a LAYOUTCOMMIT, and use it to send the layoutcommit compound.
1306  * rfc5661 is not clear about which credential should be used.
1307  *
1308  * Flexlayout client should treat DS replied FILE_SYNC as DATA_SYNC, so
1309  * to follow http://www.rfc-editor.org/errata_search.php?rfc=5661&eid=2751
1310  * we always send layoutcommit after DS writes.
1311  */
1312 static void
1313 ff_layout_set_layoutcommit(struct inode *inode,
1314                 struct pnfs_layout_segment *lseg,
1315                 loff_t end_offset)
1316 {
1317         if (!ff_layout_need_layoutcommit(lseg))
1318                 return;
1319
1320         pnfs_set_layoutcommit(inode, lseg, end_offset);
1321         dprintk("%s inode %lu pls_end_pos %llu\n", __func__, inode->i_ino,
1322                 (unsigned long long) NFS_I(inode)->layout->plh_lwb);
1323 }
1324
1325 static bool
1326 ff_layout_device_unavailable(struct pnfs_layout_segment *lseg, int idx)
1327 {
1328         /* No mirroring for now */
1329         struct nfs4_deviceid_node *node = FF_LAYOUT_DEVID_NODE(lseg, idx);
1330
1331         return ff_layout_test_devid_unavailable(node);
1332 }
1333
1334 static void ff_layout_read_record_layoutstats_start(struct rpc_task *task,
1335                 struct nfs_pgio_header *hdr)
1336 {
1337         if (test_and_set_bit(NFS_IOHDR_STAT, &hdr->flags))
1338                 return;
1339         nfs4_ff_layout_stat_io_start_read(hdr->inode,
1340                         FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
1341                         hdr->args.count,
1342                         task->tk_start);
1343 }
1344
1345 static void ff_layout_read_record_layoutstats_done(struct rpc_task *task,
1346                 struct nfs_pgio_header *hdr)
1347 {
1348         if (!test_and_clear_bit(NFS_IOHDR_STAT, &hdr->flags))
1349                 return;
1350         nfs4_ff_layout_stat_io_end_read(task,
1351                         FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
1352                         hdr->args.count,
1353                         hdr->res.count);
1354 }
1355
1356 static int ff_layout_read_prepare_common(struct rpc_task *task,
1357                                          struct nfs_pgio_header *hdr)
1358 {
1359         if (unlikely(test_bit(NFS_CONTEXT_BAD, &hdr->args.context->flags))) {
1360                 rpc_exit(task, -EIO);
1361                 return -EIO;
1362         }
1363         if (ff_layout_device_unavailable(hdr->lseg, hdr->pgio_mirror_idx)) {
1364                 rpc_exit(task, -EHOSTDOWN);
1365                 return -EAGAIN;
1366         }
1367
1368         ff_layout_read_record_layoutstats_start(task, hdr);
1369         return 0;
1370 }
1371
1372 /*
1373  * Call ops for the async read/write cases
1374  * In the case of dense layouts, the offset needs to be reset to its
1375  * original value.
1376  */
1377 static void ff_layout_read_prepare_v3(struct rpc_task *task, void *data)
1378 {
1379         struct nfs_pgio_header *hdr = data;
1380
1381         if (ff_layout_read_prepare_common(task, hdr))
1382                 return;
1383
1384         rpc_call_start(task);
1385 }
1386
1387 static int ff_layout_setup_sequence(struct nfs_client *ds_clp,
1388                                     struct nfs4_sequence_args *args,
1389                                     struct nfs4_sequence_res *res,
1390                                     struct rpc_task *task)
1391 {
1392         if (ds_clp->cl_session)
1393                 return nfs41_setup_sequence(ds_clp->cl_session,
1394                                            args,
1395                                            res,
1396                                            task);
1397         return nfs40_setup_sequence(ds_clp->cl_slot_tbl,
1398                                    args,
1399                                    res,
1400                                    task);
1401 }
1402
1403 static void ff_layout_read_prepare_v4(struct rpc_task *task, void *data)
1404 {
1405         struct nfs_pgio_header *hdr = data;
1406
1407         if (ff_layout_setup_sequence(hdr->ds_clp,
1408                                      &hdr->args.seq_args,
1409                                      &hdr->res.seq_res,
1410                                      task))
1411                 return;
1412
1413         if (ff_layout_read_prepare_common(task, hdr))
1414                 return;
1415
1416         if (nfs4_set_rw_stateid(&hdr->args.stateid, hdr->args.context,
1417                         hdr->args.lock_context, FMODE_READ) == -EIO)
1418                 rpc_exit(task, -EIO); /* lost lock, terminate I/O */
1419 }
1420
1421 static void ff_layout_read_call_done(struct rpc_task *task, void *data)
1422 {
1423         struct nfs_pgio_header *hdr = data;
1424
1425         dprintk("--> %s task->tk_status %d\n", __func__, task->tk_status);
1426
1427         if (test_bit(NFS_IOHDR_REDO, &hdr->flags) &&
1428             task->tk_status == 0) {
1429                 nfs4_sequence_done(task, &hdr->res.seq_res);
1430                 return;
1431         }
1432
1433         /* Note this may cause RPC to be resent */
1434         hdr->mds_ops->rpc_call_done(task, hdr);
1435 }
1436
1437 static void ff_layout_read_count_stats(struct rpc_task *task, void *data)
1438 {
1439         struct nfs_pgio_header *hdr = data;
1440
1441         ff_layout_read_record_layoutstats_done(task, hdr);
1442         rpc_count_iostats_metrics(task,
1443             &NFS_CLIENT(hdr->inode)->cl_metrics[NFSPROC4_CLNT_READ]);
1444 }
1445
1446 static void ff_layout_read_release(void *data)
1447 {
1448         struct nfs_pgio_header *hdr = data;
1449
1450         ff_layout_read_record_layoutstats_done(&hdr->task, hdr);
1451         pnfs_generic_rw_release(data);
1452 }
1453
1454
1455 static int ff_layout_write_done_cb(struct rpc_task *task,
1456                                 struct nfs_pgio_header *hdr)
1457 {
1458         loff_t end_offs = 0;
1459         int err;
1460
1461         trace_nfs4_pnfs_write(hdr, task->tk_status);
1462         if (task->tk_status < 0)
1463                 ff_layout_io_track_ds_error(hdr->lseg, hdr->pgio_mirror_idx,
1464                                             hdr->args.offset, hdr->args.count,
1465                                             hdr->res.op_status, OP_WRITE,
1466                                             task->tk_status);
1467         err = ff_layout_async_handle_error(task, hdr->args.context->state,
1468                                            hdr->ds_clp, hdr->lseg,
1469                                            hdr->pgio_mirror_idx);
1470
1471         switch (err) {
1472         case -NFS4ERR_RESET_TO_PNFS:
1473                 ff_layout_reset_write(hdr, true);
1474                 return task->tk_status;
1475         case -NFS4ERR_RESET_TO_MDS:
1476                 ff_layout_reset_write(hdr, false);
1477                 return task->tk_status;
1478         case -EAGAIN:
1479                 return -EAGAIN;
1480         }
1481
1482         if (hdr->res.verf->committed == NFS_FILE_SYNC ||
1483             hdr->res.verf->committed == NFS_DATA_SYNC)
1484                 end_offs = hdr->mds_offset + (loff_t)hdr->res.count;
1485
1486         /* Note: if the write is unstable, don't set end_offs until commit */
1487         ff_layout_set_layoutcommit(hdr->inode, hdr->lseg, end_offs);
1488
1489         /* zero out fattr since we don't care DS attr at all */
1490         hdr->fattr.valid = 0;
1491         if (task->tk_status >= 0)
1492                 nfs_writeback_update_inode(hdr);
1493
1494         return 0;
1495 }
1496
1497 static int ff_layout_commit_done_cb(struct rpc_task *task,
1498                                      struct nfs_commit_data *data)
1499 {
1500         int err;
1501
1502         trace_nfs4_pnfs_commit_ds(data, task->tk_status);
1503         if (task->tk_status < 0)
1504                 ff_layout_io_track_ds_error(data->lseg, data->ds_commit_index,
1505                                             data->args.offset, data->args.count,
1506                                             data->res.op_status, OP_COMMIT,
1507                                             task->tk_status);
1508         err = ff_layout_async_handle_error(task, NULL, data->ds_clp,
1509                                            data->lseg, data->ds_commit_index);
1510
1511         switch (err) {
1512         case -NFS4ERR_RESET_TO_PNFS:
1513                 pnfs_generic_prepare_to_resend_writes(data);
1514                 return -EAGAIN;
1515         case -NFS4ERR_RESET_TO_MDS:
1516                 pnfs_generic_prepare_to_resend_writes(data);
1517                 return -EAGAIN;
1518         case -EAGAIN:
1519                 rpc_restart_call_prepare(task);
1520                 return -EAGAIN;
1521         }
1522
1523         ff_layout_set_layoutcommit(data->inode, data->lseg, data->lwb);
1524
1525         return 0;
1526 }
1527
1528 static void ff_layout_write_record_layoutstats_start(struct rpc_task *task,
1529                 struct nfs_pgio_header *hdr)
1530 {
1531         if (test_and_set_bit(NFS_IOHDR_STAT, &hdr->flags))
1532                 return;
1533         nfs4_ff_layout_stat_io_start_write(hdr->inode,
1534                         FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
1535                         hdr->args.count,
1536                         task->tk_start);
1537 }
1538
1539 static void ff_layout_write_record_layoutstats_done(struct rpc_task *task,
1540                 struct nfs_pgio_header *hdr)
1541 {
1542         if (!test_and_clear_bit(NFS_IOHDR_STAT, &hdr->flags))
1543                 return;
1544         nfs4_ff_layout_stat_io_end_write(task,
1545                         FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
1546                         hdr->args.count, hdr->res.count,
1547                         hdr->res.verf->committed);
1548 }
1549
1550 static int ff_layout_write_prepare_common(struct rpc_task *task,
1551                                           struct nfs_pgio_header *hdr)
1552 {
1553         if (unlikely(test_bit(NFS_CONTEXT_BAD, &hdr->args.context->flags))) {
1554                 rpc_exit(task, -EIO);
1555                 return -EIO;
1556         }
1557
1558         if (ff_layout_device_unavailable(hdr->lseg, hdr->pgio_mirror_idx)) {
1559                 rpc_exit(task, -EHOSTDOWN);
1560                 return -EAGAIN;
1561         }
1562
1563         ff_layout_write_record_layoutstats_start(task, hdr);
1564         return 0;
1565 }
1566
1567 static void ff_layout_write_prepare_v3(struct rpc_task *task, void *data)
1568 {
1569         struct nfs_pgio_header *hdr = data;
1570
1571         if (ff_layout_write_prepare_common(task, hdr))
1572                 return;
1573
1574         rpc_call_start(task);
1575 }
1576
1577 static void ff_layout_write_prepare_v4(struct rpc_task *task, void *data)
1578 {
1579         struct nfs_pgio_header *hdr = data;
1580
1581         if (ff_layout_setup_sequence(hdr->ds_clp,
1582                                      &hdr->args.seq_args,
1583                                      &hdr->res.seq_res,
1584                                      task))
1585                 return;
1586
1587         if (ff_layout_write_prepare_common(task, hdr))
1588                 return;
1589
1590         if (nfs4_set_rw_stateid(&hdr->args.stateid, hdr->args.context,
1591                         hdr->args.lock_context, FMODE_WRITE) == -EIO)
1592                 rpc_exit(task, -EIO); /* lost lock, terminate I/O */
1593 }
1594
1595 static void ff_layout_write_call_done(struct rpc_task *task, void *data)
1596 {
1597         struct nfs_pgio_header *hdr = data;
1598
1599         if (test_bit(NFS_IOHDR_REDO, &hdr->flags) &&
1600             task->tk_status == 0) {
1601                 nfs4_sequence_done(task, &hdr->res.seq_res);
1602                 return;
1603         }
1604
1605         /* Note this may cause RPC to be resent */
1606         hdr->mds_ops->rpc_call_done(task, hdr);
1607 }
1608
1609 static void ff_layout_write_count_stats(struct rpc_task *task, void *data)
1610 {
1611         struct nfs_pgio_header *hdr = data;
1612
1613         ff_layout_write_record_layoutstats_done(task, hdr);
1614         rpc_count_iostats_metrics(task,
1615             &NFS_CLIENT(hdr->inode)->cl_metrics[NFSPROC4_CLNT_WRITE]);
1616 }
1617
1618 static void ff_layout_write_release(void *data)
1619 {
1620         struct nfs_pgio_header *hdr = data;
1621
1622         ff_layout_write_record_layoutstats_done(&hdr->task, hdr);
1623         pnfs_generic_rw_release(data);
1624 }
1625
1626 static void ff_layout_commit_record_layoutstats_start(struct rpc_task *task,
1627                 struct nfs_commit_data *cdata)
1628 {
1629         if (test_and_set_bit(NFS_IOHDR_STAT, &cdata->flags))
1630                 return;
1631         nfs4_ff_layout_stat_io_start_write(cdata->inode,
1632                         FF_LAYOUT_COMP(cdata->lseg, cdata->ds_commit_index),
1633                         0, task->tk_start);
1634 }
1635
1636 static void ff_layout_commit_record_layoutstats_done(struct rpc_task *task,
1637                 struct nfs_commit_data *cdata)
1638 {
1639         struct nfs_page *req;
1640         __u64 count = 0;
1641
1642         if (!test_and_clear_bit(NFS_IOHDR_STAT, &cdata->flags))
1643                 return;
1644
1645         if (task->tk_status == 0) {
1646                 list_for_each_entry(req, &cdata->pages, wb_list)
1647                         count += req->wb_bytes;
1648         }
1649         nfs4_ff_layout_stat_io_end_write(task,
1650                         FF_LAYOUT_COMP(cdata->lseg, cdata->ds_commit_index),
1651                         count, count, NFS_FILE_SYNC);
1652 }
1653
1654 static void ff_layout_commit_prepare_common(struct rpc_task *task,
1655                 struct nfs_commit_data *cdata)
1656 {
1657         ff_layout_commit_record_layoutstats_start(task, cdata);
1658 }
1659
1660 static void ff_layout_commit_prepare_v3(struct rpc_task *task, void *data)
1661 {
1662         ff_layout_commit_prepare_common(task, data);
1663         rpc_call_start(task);
1664 }
1665
1666 static void ff_layout_commit_prepare_v4(struct rpc_task *task, void *data)
1667 {
1668         struct nfs_commit_data *wdata = data;
1669
1670         if (ff_layout_setup_sequence(wdata->ds_clp,
1671                                  &wdata->args.seq_args,
1672                                  &wdata->res.seq_res,
1673                                  task))
1674                 return;
1675         ff_layout_commit_prepare_common(task, data);
1676 }
1677
1678 static void ff_layout_commit_done(struct rpc_task *task, void *data)
1679 {
1680         pnfs_generic_write_commit_done(task, data);
1681 }
1682
1683 static void ff_layout_commit_count_stats(struct rpc_task *task, void *data)
1684 {
1685         struct nfs_commit_data *cdata = data;
1686
1687         ff_layout_commit_record_layoutstats_done(task, cdata);
1688         rpc_count_iostats_metrics(task,
1689             &NFS_CLIENT(cdata->inode)->cl_metrics[NFSPROC4_CLNT_COMMIT]);
1690 }
1691
1692 static void ff_layout_commit_release(void *data)
1693 {
1694         struct nfs_commit_data *cdata = data;
1695
1696         ff_layout_commit_record_layoutstats_done(&cdata->task, cdata);
1697         pnfs_generic_commit_release(data);
1698 }
1699
1700 static const struct rpc_call_ops ff_layout_read_call_ops_v3 = {
1701         .rpc_call_prepare = ff_layout_read_prepare_v3,
1702         .rpc_call_done = ff_layout_read_call_done,
1703         .rpc_count_stats = ff_layout_read_count_stats,
1704         .rpc_release = ff_layout_read_release,
1705 };
1706
1707 static const struct rpc_call_ops ff_layout_read_call_ops_v4 = {
1708         .rpc_call_prepare = ff_layout_read_prepare_v4,
1709         .rpc_call_done = ff_layout_read_call_done,
1710         .rpc_count_stats = ff_layout_read_count_stats,
1711         .rpc_release = ff_layout_read_release,
1712 };
1713
1714 static const struct rpc_call_ops ff_layout_write_call_ops_v3 = {
1715         .rpc_call_prepare = ff_layout_write_prepare_v3,
1716         .rpc_call_done = ff_layout_write_call_done,
1717         .rpc_count_stats = ff_layout_write_count_stats,
1718         .rpc_release = ff_layout_write_release,
1719 };
1720
1721 static const struct rpc_call_ops ff_layout_write_call_ops_v4 = {
1722         .rpc_call_prepare = ff_layout_write_prepare_v4,
1723         .rpc_call_done = ff_layout_write_call_done,
1724         .rpc_count_stats = ff_layout_write_count_stats,
1725         .rpc_release = ff_layout_write_release,
1726 };
1727
1728 static const struct rpc_call_ops ff_layout_commit_call_ops_v3 = {
1729         .rpc_call_prepare = ff_layout_commit_prepare_v3,
1730         .rpc_call_done = ff_layout_commit_done,
1731         .rpc_count_stats = ff_layout_commit_count_stats,
1732         .rpc_release = ff_layout_commit_release,
1733 };
1734
1735 static const struct rpc_call_ops ff_layout_commit_call_ops_v4 = {
1736         .rpc_call_prepare = ff_layout_commit_prepare_v4,
1737         .rpc_call_done = ff_layout_commit_done,
1738         .rpc_count_stats = ff_layout_commit_count_stats,
1739         .rpc_release = ff_layout_commit_release,
1740 };
1741
1742 static enum pnfs_try_status
1743 ff_layout_read_pagelist(struct nfs_pgio_header *hdr)
1744 {
1745         struct pnfs_layout_segment *lseg = hdr->lseg;
1746         struct nfs4_pnfs_ds *ds;
1747         struct rpc_clnt *ds_clnt;
1748         struct rpc_cred *ds_cred;
1749         loff_t offset = hdr->args.offset;
1750         u32 idx = hdr->pgio_mirror_idx;
1751         int vers;
1752         struct nfs_fh *fh;
1753
1754         dprintk("--> %s ino %lu pgbase %u req %Zu@%llu\n",
1755                 __func__, hdr->inode->i_ino,
1756                 hdr->args.pgbase, (size_t)hdr->args.count, offset);
1757
1758         ds = nfs4_ff_layout_prepare_ds(lseg, idx, false);
1759         if (!ds)
1760                 goto out_failed;
1761
1762         ds_clnt = nfs4_ff_find_or_create_ds_client(lseg, idx, ds->ds_clp,
1763                                                    hdr->inode);
1764         if (IS_ERR(ds_clnt))
1765                 goto out_failed;
1766
1767         ds_cred = ff_layout_get_ds_cred(lseg, idx, hdr->cred);
1768         if (!ds_cred)
1769                 goto out_failed;
1770
1771         vers = nfs4_ff_layout_ds_version(lseg, idx);
1772
1773         dprintk("%s USE DS: %s cl_count %d vers %d\n", __func__,
1774                 ds->ds_remotestr, atomic_read(&ds->ds_clp->cl_count), vers);
1775
1776         hdr->pgio_done_cb = ff_layout_read_done_cb;
1777         atomic_inc(&ds->ds_clp->cl_count);
1778         hdr->ds_clp = ds->ds_clp;
1779         fh = nfs4_ff_layout_select_ds_fh(lseg, idx);
1780         if (fh)
1781                 hdr->args.fh = fh;
1782         /*
1783          * Note that if we ever decide to split across DSes,
1784          * then we may need to handle dense-like offsets.
1785          */
1786         hdr->args.offset = offset;
1787         hdr->mds_offset = offset;
1788
1789         /* Perform an asynchronous read to ds */
1790         nfs_initiate_pgio(ds_clnt, hdr, ds_cred, ds->ds_clp->rpc_ops,
1791                           vers == 3 ? &ff_layout_read_call_ops_v3 :
1792                                       &ff_layout_read_call_ops_v4,
1793                           0, RPC_TASK_SOFTCONN);
1794         put_rpccred(ds_cred);
1795         return PNFS_ATTEMPTED;
1796
1797 out_failed:
1798         if (ff_layout_avoid_mds_available_ds(lseg))
1799                 return PNFS_TRY_AGAIN;
1800         return PNFS_NOT_ATTEMPTED;
1801 }
1802
1803 /* Perform async writes. */
1804 static enum pnfs_try_status
1805 ff_layout_write_pagelist(struct nfs_pgio_header *hdr, int sync)
1806 {
1807         struct pnfs_layout_segment *lseg = hdr->lseg;
1808         struct nfs4_pnfs_ds *ds;
1809         struct rpc_clnt *ds_clnt;
1810         struct rpc_cred *ds_cred;
1811         loff_t offset = hdr->args.offset;
1812         int vers;
1813         struct nfs_fh *fh;
1814         int idx = hdr->pgio_mirror_idx;
1815
1816         ds = nfs4_ff_layout_prepare_ds(lseg, idx, true);
1817         if (!ds)
1818                 return PNFS_NOT_ATTEMPTED;
1819
1820         ds_clnt = nfs4_ff_find_or_create_ds_client(lseg, idx, ds->ds_clp,
1821                                                    hdr->inode);
1822         if (IS_ERR(ds_clnt))
1823                 return PNFS_NOT_ATTEMPTED;
1824
1825         ds_cred = ff_layout_get_ds_cred(lseg, idx, hdr->cred);
1826         if (!ds_cred)
1827                 return PNFS_NOT_ATTEMPTED;
1828
1829         vers = nfs4_ff_layout_ds_version(lseg, idx);
1830
1831         dprintk("%s ino %lu sync %d req %Zu@%llu DS: %s cl_count %d vers %d\n",
1832                 __func__, hdr->inode->i_ino, sync, (size_t) hdr->args.count,
1833                 offset, ds->ds_remotestr, atomic_read(&ds->ds_clp->cl_count),
1834                 vers);
1835
1836         hdr->pgio_done_cb = ff_layout_write_done_cb;
1837         atomic_inc(&ds->ds_clp->cl_count);
1838         hdr->ds_clp = ds->ds_clp;
1839         hdr->ds_commit_idx = idx;
1840         fh = nfs4_ff_layout_select_ds_fh(lseg, idx);
1841         if (fh)
1842                 hdr->args.fh = fh;
1843
1844         /*
1845          * Note that if we ever decide to split across DSes,
1846          * then we may need to handle dense-like offsets.
1847          */
1848         hdr->args.offset = offset;
1849
1850         /* Perform an asynchronous write */
1851         nfs_initiate_pgio(ds_clnt, hdr, ds_cred, ds->ds_clp->rpc_ops,
1852                           vers == 3 ? &ff_layout_write_call_ops_v3 :
1853                                       &ff_layout_write_call_ops_v4,
1854                           sync, RPC_TASK_SOFTCONN);
1855         put_rpccred(ds_cred);
1856         return PNFS_ATTEMPTED;
1857 }
1858
1859 static u32 calc_ds_index_from_commit(struct pnfs_layout_segment *lseg, u32 i)
1860 {
1861         return i;
1862 }
1863
1864 static struct nfs_fh *
1865 select_ds_fh_from_commit(struct pnfs_layout_segment *lseg, u32 i)
1866 {
1867         struct nfs4_ff_layout_segment *flseg = FF_LAYOUT_LSEG(lseg);
1868
1869         /* FIXME: Assume that there is only one NFS version available
1870          * for the DS.
1871          */
1872         return &flseg->mirror_array[i]->fh_versions[0];
1873 }
1874
1875 static int ff_layout_initiate_commit(struct nfs_commit_data *data, int how)
1876 {
1877         struct pnfs_layout_segment *lseg = data->lseg;
1878         struct nfs4_pnfs_ds *ds;
1879         struct rpc_clnt *ds_clnt;
1880         struct rpc_cred *ds_cred;
1881         u32 idx;
1882         int vers, ret;
1883         struct nfs_fh *fh;
1884
1885         idx = calc_ds_index_from_commit(lseg, data->ds_commit_index);
1886         ds = nfs4_ff_layout_prepare_ds(lseg, idx, true);
1887         if (!ds)
1888                 goto out_err;
1889
1890         ds_clnt = nfs4_ff_find_or_create_ds_client(lseg, idx, ds->ds_clp,
1891                                                    data->inode);
1892         if (IS_ERR(ds_clnt))
1893                 goto out_err;
1894
1895         ds_cred = ff_layout_get_ds_cred(lseg, idx, data->cred);
1896         if (!ds_cred)
1897                 goto out_err;
1898
1899         vers = nfs4_ff_layout_ds_version(lseg, idx);
1900
1901         dprintk("%s ino %lu, how %d cl_count %d vers %d\n", __func__,
1902                 data->inode->i_ino, how, atomic_read(&ds->ds_clp->cl_count),
1903                 vers);
1904         data->commit_done_cb = ff_layout_commit_done_cb;
1905         data->cred = ds_cred;
1906         atomic_inc(&ds->ds_clp->cl_count);
1907         data->ds_clp = ds->ds_clp;
1908         fh = select_ds_fh_from_commit(lseg, data->ds_commit_index);
1909         if (fh)
1910                 data->args.fh = fh;
1911
1912         ret = nfs_initiate_commit(ds_clnt, data, ds->ds_clp->rpc_ops,
1913                                    vers == 3 ? &ff_layout_commit_call_ops_v3 :
1914                                                &ff_layout_commit_call_ops_v4,
1915                                    how, RPC_TASK_SOFTCONN);
1916         put_rpccred(ds_cred);
1917         return ret;
1918 out_err:
1919         pnfs_generic_prepare_to_resend_writes(data);
1920         pnfs_generic_commit_release(data);
1921         return -EAGAIN;
1922 }
1923
1924 static int
1925 ff_layout_commit_pagelist(struct inode *inode, struct list_head *mds_pages,
1926                            int how, struct nfs_commit_info *cinfo)
1927 {
1928         return pnfs_generic_commit_pagelist(inode, mds_pages, how, cinfo,
1929                                             ff_layout_initiate_commit);
1930 }
1931
1932 static struct pnfs_ds_commit_info *
1933 ff_layout_get_ds_info(struct inode *inode)
1934 {
1935         struct pnfs_layout_hdr *layout = NFS_I(inode)->layout;
1936
1937         if (layout == NULL)
1938                 return NULL;
1939
1940         return &FF_LAYOUT_FROM_HDR(layout)->commit_info;
1941 }
1942
1943 static void
1944 ff_layout_free_deviceid_node(struct nfs4_deviceid_node *d)
1945 {
1946         nfs4_ff_layout_free_deviceid(container_of(d, struct nfs4_ff_layout_ds,
1947                                                   id_node));
1948 }
1949
1950 static int ff_layout_encode_ioerr(struct xdr_stream *xdr,
1951                                   const struct nfs4_layoutreturn_args *args,
1952                                   const struct nfs4_flexfile_layoutreturn_args *ff_args)
1953 {
1954         __be32 *start;
1955
1956         start = xdr_reserve_space(xdr, 4);
1957         if (unlikely(!start))
1958                 return -E2BIG;
1959
1960         *start = cpu_to_be32(ff_args->num_errors);
1961         /* This assume we always return _ALL_ layouts */
1962         return ff_layout_encode_ds_ioerr(xdr, &ff_args->errors);
1963 }
1964
1965 static void
1966 encode_opaque_fixed(struct xdr_stream *xdr, const void *buf, size_t len)
1967 {
1968         __be32 *p;
1969
1970         p = xdr_reserve_space(xdr, len);
1971         xdr_encode_opaque_fixed(p, buf, len);
1972 }
1973
1974 static void
1975 ff_layout_encode_ff_iostat_head(struct xdr_stream *xdr,
1976                             const nfs4_stateid *stateid,
1977                             const struct nfs42_layoutstat_devinfo *devinfo)
1978 {
1979         __be32 *p;
1980
1981         p = xdr_reserve_space(xdr, 8 + 8);
1982         p = xdr_encode_hyper(p, devinfo->offset);
1983         p = xdr_encode_hyper(p, devinfo->length);
1984         encode_opaque_fixed(xdr, stateid->data, NFS4_STATEID_SIZE);
1985         p = xdr_reserve_space(xdr, 4*8);
1986         p = xdr_encode_hyper(p, devinfo->read_count);
1987         p = xdr_encode_hyper(p, devinfo->read_bytes);
1988         p = xdr_encode_hyper(p, devinfo->write_count);
1989         p = xdr_encode_hyper(p, devinfo->write_bytes);
1990         encode_opaque_fixed(xdr, devinfo->dev_id.data, NFS4_DEVICEID4_SIZE);
1991 }
1992
1993 static void
1994 ff_layout_encode_ff_iostat(struct xdr_stream *xdr,
1995                             const nfs4_stateid *stateid,
1996                             const struct nfs42_layoutstat_devinfo *devinfo)
1997 {
1998         ff_layout_encode_ff_iostat_head(xdr, stateid, devinfo);
1999         ff_layout_encode_ff_layoutupdate(xdr, devinfo,
2000                         devinfo->ld_private.data);
2001 }
2002
2003 /* report nothing for now */
2004 static void ff_layout_encode_iostats_array(struct xdr_stream *xdr,
2005                 const struct nfs4_layoutreturn_args *args,
2006                 struct nfs4_flexfile_layoutreturn_args *ff_args)
2007 {
2008         __be32 *p;
2009         int i;
2010
2011         p = xdr_reserve_space(xdr, 4);
2012         *p = cpu_to_be32(ff_args->num_dev);
2013         for (i = 0; i < ff_args->num_dev; i++)
2014                 ff_layout_encode_ff_iostat(xdr,
2015                                 &args->layout->plh_stateid,
2016                                 &ff_args->devinfo[i]);
2017 }
2018
2019 static void
2020 ff_layout_free_iostats_array(struct nfs42_layoutstat_devinfo *devinfo,
2021                 unsigned int num_entries)
2022 {
2023         unsigned int i;
2024
2025         for (i = 0; i < num_entries; i++) {
2026                 if (!devinfo[i].ld_private.ops)
2027                         continue;
2028                 if (!devinfo[i].ld_private.ops->free)
2029                         continue;
2030                 devinfo[i].ld_private.ops->free(&devinfo[i].ld_private);
2031         }
2032 }
2033
2034 static struct nfs4_deviceid_node *
2035 ff_layout_alloc_deviceid_node(struct nfs_server *server,
2036                               struct pnfs_device *pdev, gfp_t gfp_flags)
2037 {
2038         struct nfs4_ff_layout_ds *dsaddr;
2039
2040         dsaddr = nfs4_ff_alloc_deviceid_node(server, pdev, gfp_flags);
2041         if (!dsaddr)
2042                 return NULL;
2043         return &dsaddr->id_node;
2044 }
2045
2046 static void
2047 ff_layout_encode_layoutreturn(struct xdr_stream *xdr,
2048                 const void *voidargs,
2049                 const struct nfs4_xdr_opaque_data *ff_opaque)
2050 {
2051         const struct nfs4_layoutreturn_args *args = voidargs;
2052         struct nfs4_flexfile_layoutreturn_args *ff_args = ff_opaque->data;
2053         struct xdr_buf tmp_buf = {
2054                 .head = {
2055                         [0] = {
2056                                 .iov_base = page_address(ff_args->pages[0]),
2057                         },
2058                 },
2059                 .buflen = PAGE_SIZE,
2060         };
2061         struct xdr_stream tmp_xdr;
2062         __be32 *start;
2063
2064         dprintk("%s: Begin\n", __func__);
2065
2066         xdr_init_encode(&tmp_xdr, &tmp_buf, NULL);
2067
2068         ff_layout_encode_ioerr(&tmp_xdr, args, ff_args);
2069         ff_layout_encode_iostats_array(&tmp_xdr, args, ff_args);
2070
2071         start = xdr_reserve_space(xdr, 4);
2072         *start = cpu_to_be32(tmp_buf.len);
2073         xdr_write_pages(xdr, ff_args->pages, 0, tmp_buf.len);
2074
2075         dprintk("%s: Return\n", __func__);
2076 }
2077
2078 static void
2079 ff_layout_free_layoutreturn(struct nfs4_xdr_opaque_data *args)
2080 {
2081         struct nfs4_flexfile_layoutreturn_args *ff_args;
2082
2083         if (!args->data)
2084                 return;
2085         ff_args = args->data;
2086         args->data = NULL;
2087
2088         ff_layout_free_ds_ioerr(&ff_args->errors);
2089         ff_layout_free_iostats_array(ff_args->devinfo, ff_args->num_dev);
2090
2091         put_page(ff_args->pages[0]);
2092         kfree(ff_args);
2093 }
2094
2095 const struct nfs4_xdr_opaque_ops layoutreturn_ops = {
2096         .encode = ff_layout_encode_layoutreturn,
2097         .free = ff_layout_free_layoutreturn,
2098 };
2099
2100 static int
2101 ff_layout_prepare_layoutreturn(struct nfs4_layoutreturn_args *args)
2102 {
2103         struct nfs4_flexfile_layoutreturn_args *ff_args;
2104         struct nfs4_flexfile_layout *ff_layout = FF_LAYOUT_FROM_HDR(args->layout);
2105
2106         ff_args = kmalloc(sizeof(*ff_args), GFP_KERNEL);
2107         if (!ff_args)
2108                 goto out_nomem;
2109         ff_args->pages[0] = alloc_page(GFP_KERNEL);
2110         if (!ff_args->pages[0])
2111                 goto out_nomem_free;
2112
2113         INIT_LIST_HEAD(&ff_args->errors);
2114         ff_args->num_errors = ff_layout_fetch_ds_ioerr(args->layout,
2115                         &args->range, &ff_args->errors,
2116                         FF_LAYOUTRETURN_MAXERR);
2117
2118         spin_lock(&args->inode->i_lock);
2119         ff_args->num_dev = ff_layout_mirror_prepare_stats(&ff_layout->generic_hdr,
2120                         &ff_args->devinfo[0], ARRAY_SIZE(ff_args->devinfo));
2121         spin_unlock(&args->inode->i_lock);
2122
2123         args->ld_private->ops = &layoutreturn_ops;
2124         args->ld_private->data = ff_args;
2125         return 0;
2126 out_nomem_free:
2127         kfree(ff_args);
2128 out_nomem:
2129         return -ENOMEM;
2130 }
2131
2132 static int
2133 ff_layout_ntop4(const struct sockaddr *sap, char *buf, const size_t buflen)
2134 {
2135         const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
2136
2137         return snprintf(buf, buflen, "%pI4", &sin->sin_addr);
2138 }
2139
2140 static size_t
2141 ff_layout_ntop6_noscopeid(const struct sockaddr *sap, char *buf,
2142                           const int buflen)
2143 {
2144         const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
2145         const struct in6_addr *addr = &sin6->sin6_addr;
2146
2147         /*
2148          * RFC 4291, Section 2.2.2
2149          *
2150          * Shorthanded ANY address
2151          */
2152         if (ipv6_addr_any(addr))
2153                 return snprintf(buf, buflen, "::");
2154
2155         /*
2156          * RFC 4291, Section 2.2.2
2157          *
2158          * Shorthanded loopback address
2159          */
2160         if (ipv6_addr_loopback(addr))
2161                 return snprintf(buf, buflen, "::1");
2162
2163         /*
2164          * RFC 4291, Section 2.2.3
2165          *
2166          * Special presentation address format for mapped v4
2167          * addresses.
2168          */
2169         if (ipv6_addr_v4mapped(addr))
2170                 return snprintf(buf, buflen, "::ffff:%pI4",
2171                                         &addr->s6_addr32[3]);
2172
2173         /*
2174          * RFC 4291, Section 2.2.1
2175          */
2176         return snprintf(buf, buflen, "%pI6c", addr);
2177 }
2178
2179 /* Derived from rpc_sockaddr2uaddr */
2180 static void
2181 ff_layout_encode_netaddr(struct xdr_stream *xdr, struct nfs4_pnfs_ds_addr *da)
2182 {
2183         struct sockaddr *sap = (struct sockaddr *)&da->da_addr;
2184         char portbuf[RPCBIND_MAXUADDRPLEN];
2185         char addrbuf[RPCBIND_MAXUADDRLEN];
2186         char *netid;
2187         unsigned short port;
2188         int len, netid_len;
2189         __be32 *p;
2190
2191         switch (sap->sa_family) {
2192         case AF_INET:
2193                 if (ff_layout_ntop4(sap, addrbuf, sizeof(addrbuf)) == 0)
2194                         return;
2195                 port = ntohs(((struct sockaddr_in *)sap)->sin_port);
2196                 netid = "tcp";
2197                 netid_len = 3;
2198                 break;
2199         case AF_INET6:
2200                 if (ff_layout_ntop6_noscopeid(sap, addrbuf, sizeof(addrbuf)) == 0)
2201                         return;
2202                 port = ntohs(((struct sockaddr_in6 *)sap)->sin6_port);
2203                 netid = "tcp6";
2204                 netid_len = 4;
2205                 break;
2206         default:
2207                 /* we only support tcp and tcp6 */
2208                 WARN_ON_ONCE(1);
2209                 return;
2210         }
2211
2212         snprintf(portbuf, sizeof(portbuf), ".%u.%u", port >> 8, port & 0xff);
2213         len = strlcat(addrbuf, portbuf, sizeof(addrbuf));
2214
2215         p = xdr_reserve_space(xdr, 4 + netid_len);
2216         xdr_encode_opaque(p, netid, netid_len);
2217
2218         p = xdr_reserve_space(xdr, 4 + len);
2219         xdr_encode_opaque(p, addrbuf, len);
2220 }
2221
2222 static void
2223 ff_layout_encode_nfstime(struct xdr_stream *xdr,
2224                          ktime_t t)
2225 {
2226         struct timespec64 ts;
2227         __be32 *p;
2228
2229         p = xdr_reserve_space(xdr, 12);
2230         ts = ktime_to_timespec64(t);
2231         p = xdr_encode_hyper(p, ts.tv_sec);
2232         *p++ = cpu_to_be32(ts.tv_nsec);
2233 }
2234
2235 static void
2236 ff_layout_encode_io_latency(struct xdr_stream *xdr,
2237                             struct nfs4_ff_io_stat *stat)
2238 {
2239         __be32 *p;
2240
2241         p = xdr_reserve_space(xdr, 5 * 8);
2242         p = xdr_encode_hyper(p, stat->ops_requested);
2243         p = xdr_encode_hyper(p, stat->bytes_requested);
2244         p = xdr_encode_hyper(p, stat->ops_completed);
2245         p = xdr_encode_hyper(p, stat->bytes_completed);
2246         p = xdr_encode_hyper(p, stat->bytes_not_delivered);
2247         ff_layout_encode_nfstime(xdr, stat->total_busy_time);
2248         ff_layout_encode_nfstime(xdr, stat->aggregate_completion_time);
2249 }
2250
2251 static void
2252 ff_layout_encode_ff_layoutupdate(struct xdr_stream *xdr,
2253                               const struct nfs42_layoutstat_devinfo *devinfo,
2254                               struct nfs4_ff_layout_mirror *mirror)
2255 {
2256         struct nfs4_pnfs_ds_addr *da;
2257         struct nfs4_pnfs_ds *ds = mirror->mirror_ds->ds;
2258         struct nfs_fh *fh = &mirror->fh_versions[0];
2259         __be32 *p;
2260
2261         da = list_first_entry(&ds->ds_addrs, struct nfs4_pnfs_ds_addr, da_node);
2262         dprintk("%s: DS %s: encoding address %s\n",
2263                 __func__, ds->ds_remotestr, da->da_remotestr);
2264         /* netaddr4 */
2265         ff_layout_encode_netaddr(xdr, da);
2266         /* nfs_fh4 */
2267         p = xdr_reserve_space(xdr, 4 + fh->size);
2268         xdr_encode_opaque(p, fh->data, fh->size);
2269         /* ff_io_latency4 read */
2270         spin_lock(&mirror->lock);
2271         ff_layout_encode_io_latency(xdr, &mirror->read_stat.io_stat);
2272         /* ff_io_latency4 write */
2273         ff_layout_encode_io_latency(xdr, &mirror->write_stat.io_stat);
2274         spin_unlock(&mirror->lock);
2275         /* nfstime4 */
2276         ff_layout_encode_nfstime(xdr, ktime_sub(ktime_get(), mirror->start_time));
2277         /* bool */
2278         p = xdr_reserve_space(xdr, 4);
2279         *p = cpu_to_be32(false);
2280 }
2281
2282 static void
2283 ff_layout_encode_layoutstats(struct xdr_stream *xdr, const void *args,
2284                              const struct nfs4_xdr_opaque_data *opaque)
2285 {
2286         struct nfs42_layoutstat_devinfo *devinfo = container_of(opaque,
2287                         struct nfs42_layoutstat_devinfo, ld_private);
2288         __be32 *start;
2289
2290         /* layoutupdate length */
2291         start = xdr_reserve_space(xdr, 4);
2292         ff_layout_encode_ff_layoutupdate(xdr, devinfo, opaque->data);
2293
2294         *start = cpu_to_be32((xdr->p - start - 1) * 4);
2295 }
2296
2297 static void
2298 ff_layout_free_layoutstats(struct nfs4_xdr_opaque_data *opaque)
2299 {
2300         struct nfs4_ff_layout_mirror *mirror = opaque->data;
2301
2302         ff_layout_put_mirror(mirror);
2303 }
2304
2305 static const struct nfs4_xdr_opaque_ops layoutstat_ops = {
2306         .encode = ff_layout_encode_layoutstats,
2307         .free   = ff_layout_free_layoutstats,
2308 };
2309
2310 static int
2311 ff_layout_mirror_prepare_stats(struct pnfs_layout_hdr *lo,
2312                                struct nfs42_layoutstat_devinfo *devinfo,
2313                                int dev_limit)
2314 {
2315         struct nfs4_flexfile_layout *ff_layout = FF_LAYOUT_FROM_HDR(lo);
2316         struct nfs4_ff_layout_mirror *mirror;
2317         struct nfs4_deviceid_node *dev;
2318         int i = 0;
2319
2320         list_for_each_entry(mirror, &ff_layout->mirrors, mirrors) {
2321                 if (i >= dev_limit)
2322                         break;
2323                 if (IS_ERR_OR_NULL(mirror->mirror_ds))
2324                         continue;
2325                 if (!test_and_clear_bit(NFS4_FF_MIRROR_STAT_AVAIL, &mirror->flags))
2326                         continue;
2327                 /* mirror refcount put in cleanup_layoutstats */
2328                 if (!atomic_inc_not_zero(&mirror->ref))
2329                         continue;
2330                 dev = &mirror->mirror_ds->id_node;
2331                 memcpy(&devinfo->dev_id, &dev->deviceid, NFS4_DEVICEID4_SIZE);
2332                 devinfo->offset = 0;
2333                 devinfo->length = NFS4_MAX_UINT64;
2334                 spin_lock(&mirror->lock);
2335                 devinfo->read_count = mirror->read_stat.io_stat.ops_completed;
2336                 devinfo->read_bytes = mirror->read_stat.io_stat.bytes_completed;
2337                 devinfo->write_count = mirror->write_stat.io_stat.ops_completed;
2338                 devinfo->write_bytes = mirror->write_stat.io_stat.bytes_completed;
2339                 spin_unlock(&mirror->lock);
2340                 devinfo->layout_type = LAYOUT_FLEX_FILES;
2341                 devinfo->ld_private.ops = &layoutstat_ops;
2342                 devinfo->ld_private.data = mirror;
2343
2344                 devinfo++;
2345                 i++;
2346         }
2347         return i;
2348 }
2349
2350 static int
2351 ff_layout_prepare_layoutstats(struct nfs42_layoutstat_args *args)
2352 {
2353         struct nfs4_flexfile_layout *ff_layout;
2354         const int dev_count = PNFS_LAYOUTSTATS_MAXDEV;
2355
2356         /* For now, send at most PNFS_LAYOUTSTATS_MAXDEV statistics */
2357         args->devinfo = kmalloc_array(dev_count, sizeof(*args->devinfo), GFP_NOIO);
2358         if (!args->devinfo)
2359                 return -ENOMEM;
2360
2361         spin_lock(&args->inode->i_lock);
2362         ff_layout = FF_LAYOUT_FROM_HDR(NFS_I(args->inode)->layout);
2363         args->num_dev = ff_layout_mirror_prepare_stats(&ff_layout->generic_hdr,
2364                         &args->devinfo[0], dev_count);
2365         spin_unlock(&args->inode->i_lock);
2366         if (!args->num_dev) {
2367                 kfree(args->devinfo);
2368                 args->devinfo = NULL;
2369                 return -ENOENT;
2370         }
2371
2372         return 0;
2373 }
2374
2375 static struct pnfs_layoutdriver_type flexfilelayout_type = {
2376         .id                     = LAYOUT_FLEX_FILES,
2377         .name                   = "LAYOUT_FLEX_FILES",
2378         .owner                  = THIS_MODULE,
2379         .alloc_layout_hdr       = ff_layout_alloc_layout_hdr,
2380         .free_layout_hdr        = ff_layout_free_layout_hdr,
2381         .alloc_lseg             = ff_layout_alloc_lseg,
2382         .free_lseg              = ff_layout_free_lseg,
2383         .add_lseg               = ff_layout_add_lseg,
2384         .pg_read_ops            = &ff_layout_pg_read_ops,
2385         .pg_write_ops           = &ff_layout_pg_write_ops,
2386         .get_ds_info            = ff_layout_get_ds_info,
2387         .free_deviceid_node     = ff_layout_free_deviceid_node,
2388         .mark_request_commit    = pnfs_layout_mark_request_commit,
2389         .clear_request_commit   = pnfs_generic_clear_request_commit,
2390         .scan_commit_lists      = pnfs_generic_scan_commit_lists,
2391         .recover_commit_reqs    = pnfs_generic_recover_commit_reqs,
2392         .commit_pagelist        = ff_layout_commit_pagelist,
2393         .read_pagelist          = ff_layout_read_pagelist,
2394         .write_pagelist         = ff_layout_write_pagelist,
2395         .alloc_deviceid_node    = ff_layout_alloc_deviceid_node,
2396         .prepare_layoutreturn   = ff_layout_prepare_layoutreturn,
2397         .sync                   = pnfs_nfs_generic_sync,
2398         .prepare_layoutstats    = ff_layout_prepare_layoutstats,
2399 };
2400
2401 static int __init nfs4flexfilelayout_init(void)
2402 {
2403         printk(KERN_INFO "%s: NFSv4 Flexfile Layout Driver Registering...\n",
2404                __func__);
2405         if (!ff_zero_group) {
2406                 ff_zero_group = groups_alloc(0);
2407                 if (!ff_zero_group)
2408                         return -ENOMEM;
2409         }
2410         return pnfs_register_layoutdriver(&flexfilelayout_type);
2411 }
2412
2413 static void __exit nfs4flexfilelayout_exit(void)
2414 {
2415         printk(KERN_INFO "%s: NFSv4 Flexfile Layout Driver Unregistering...\n",
2416                __func__);
2417         pnfs_unregister_layoutdriver(&flexfilelayout_type);
2418         if (ff_zero_group) {
2419                 put_group_info(ff_zero_group);
2420                 ff_zero_group = NULL;
2421         }
2422 }
2423
2424 MODULE_ALIAS("nfs-layouttype4-4");
2425
2426 MODULE_LICENSE("GPL");
2427 MODULE_DESCRIPTION("The NFSv4 flexfile layout driver");
2428
2429 module_init(nfs4flexfilelayout_init);
2430 module_exit(nfs4flexfilelayout_exit);