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 (!mirror->start_time)
 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         switch (task->tk_status) {
1057         /* MDS state errors */
1058         case -NFS4ERR_DELEG_REVOKED:
1059         case -NFS4ERR_ADMIN_REVOKED:
1060         case -NFS4ERR_BAD_STATEID:
1061                 if (state == NULL)
1062                         break;
1063                 nfs_remove_bad_delegation(state->inode, NULL);
1064         case -NFS4ERR_OPENMODE:
1065                 if (state == NULL)
1066                         break;
1067                 if (nfs4_schedule_stateid_recovery(mds_server, state) < 0)
1068                         goto out_bad_stateid;
1069                 goto wait_on_recovery;
1070         case -NFS4ERR_EXPIRED:
1071                 if (state != NULL) {
1072                         if (nfs4_schedule_stateid_recovery(mds_server, state) < 0)
1073                                 goto out_bad_stateid;
1074                 }
1075                 nfs4_schedule_lease_recovery(mds_client);
1076                 goto wait_on_recovery;
1077         /* DS session errors */
1078         case -NFS4ERR_BADSESSION:
1079         case -NFS4ERR_BADSLOT:
1080         case -NFS4ERR_BAD_HIGH_SLOT:
1081         case -NFS4ERR_DEADSESSION:
1082         case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1083         case -NFS4ERR_SEQ_FALSE_RETRY:
1084         case -NFS4ERR_SEQ_MISORDERED:
1085                 dprintk("%s ERROR %d, Reset session. Exchangeid "
1086                         "flags 0x%x\n", __func__, task->tk_status,
1087                         clp->cl_exchange_flags);
1088                 nfs4_schedule_session_recovery(clp->cl_session, task->tk_status);
1089                 break;
1090         case -NFS4ERR_DELAY:
1091         case -NFS4ERR_GRACE:
1092                 rpc_delay(task, FF_LAYOUT_POLL_RETRY_MAX);
1093                 break;
1094         case -NFS4ERR_RETRY_UNCACHED_REP:
1095                 break;
1096         /* Invalidate Layout errors */
1097         case -NFS4ERR_PNFS_NO_LAYOUT:
1098         case -ESTALE:           /* mapped NFS4ERR_STALE */
1099         case -EBADHANDLE:       /* mapped NFS4ERR_BADHANDLE */
1100         case -EISDIR:           /* mapped NFS4ERR_ISDIR */
1101         case -NFS4ERR_FHEXPIRED:
1102         case -NFS4ERR_WRONG_TYPE:
1103                 dprintk("%s Invalid layout error %d\n", __func__,
1104                         task->tk_status);
1105                 /*
1106                  * Destroy layout so new i/o will get a new layout.
1107                  * Layout will not be destroyed until all current lseg
1108                  * references are put. Mark layout as invalid to resend failed
1109                  * i/o and all i/o waiting on the slot table to the MDS until
1110                  * layout is destroyed and a new valid layout is obtained.
1111                  */
1112                 pnfs_destroy_layout(NFS_I(inode));
1113                 rpc_wake_up(&tbl->slot_tbl_waitq);
1114                 goto reset;
1115         /* RPC connection errors */
1116         case -ECONNREFUSED:
1117         case -EHOSTDOWN:
1118         case -EHOSTUNREACH:
1119         case -ENETUNREACH:
1120         case -EIO:
1121         case -ETIMEDOUT:
1122         case -EPIPE:
1123                 dprintk("%s DS connection error %d\n", __func__,
1124                         task->tk_status);
1125                 nfs4_delete_deviceid(devid->ld, devid->nfs_client,
1126                                 &devid->deviceid);
1127                 rpc_wake_up(&tbl->slot_tbl_waitq);
1128                 /* fall through */
1129         default:
1130                 if (ff_layout_avoid_mds_available_ds(lseg))
1131                         return -NFS4ERR_RESET_TO_PNFS;
1132 reset:
1133                 dprintk("%s Retry through MDS. Error %d\n", __func__,
1134                         task->tk_status);
1135                 return -NFS4ERR_RESET_TO_MDS;
1136         }
1137 out:
1138         task->tk_status = 0;
1139         return -EAGAIN;
1140 out_bad_stateid:
1141         task->tk_status = -EIO;
1142         return 0;
1143 wait_on_recovery:
1144         rpc_sleep_on(&mds_client->cl_rpcwaitq, task, NULL);
1145         if (test_bit(NFS4CLNT_MANAGER_RUNNING, &mds_client->cl_state) == 0)
1146                 rpc_wake_up_queued_task(&mds_client->cl_rpcwaitq, task);
1147         goto out;
1148 }
1149
1150 /* Retry all errors through either pNFS or MDS except for -EJUKEBOX */
1151 static int ff_layout_async_handle_error_v3(struct rpc_task *task,
1152                                            struct pnfs_layout_segment *lseg,
1153                                            int idx)
1154 {
1155         struct nfs4_deviceid_node *devid = FF_LAYOUT_DEVID_NODE(lseg, idx);
1156
1157         switch (task->tk_status) {
1158         /* File access problems. Don't mark the device as unavailable */
1159         case -EACCES:
1160         case -ESTALE:
1161         case -EISDIR:
1162         case -EBADHANDLE:
1163         case -ELOOP:
1164         case -ENOSPC:
1165                 break;
1166         case -EJUKEBOX:
1167                 nfs_inc_stats(lseg->pls_layout->plh_inode, NFSIOS_DELAY);
1168                 goto out_retry;
1169         default:
1170                 dprintk("%s DS connection error %d\n", __func__,
1171                         task->tk_status);
1172                 nfs4_delete_deviceid(devid->ld, devid->nfs_client,
1173                                 &devid->deviceid);
1174         }
1175         /* FIXME: Need to prevent infinite looping here. */
1176         return -NFS4ERR_RESET_TO_PNFS;
1177 out_retry:
1178         task->tk_status = 0;
1179         rpc_restart_call_prepare(task);
1180         rpc_delay(task, NFS_JUKEBOX_RETRY_TIME);
1181         return -EAGAIN;
1182 }
1183
1184 static int ff_layout_async_handle_error(struct rpc_task *task,
1185                                         struct nfs4_state *state,
1186                                         struct nfs_client *clp,
1187                                         struct pnfs_layout_segment *lseg,
1188                                         int idx)
1189 {
1190         int vers = clp->cl_nfs_mod->rpc_vers->number;
1191
1192         if (task->tk_status >= 0)
1193                 return 0;
1194
1195         /* Handle the case of an invalid layout segment */
1196         if (!pnfs_is_valid_lseg(lseg))
1197                 return -NFS4ERR_RESET_TO_PNFS;
1198
1199         switch (vers) {
1200         case 3:
1201                 return ff_layout_async_handle_error_v3(task, lseg, idx);
1202         case 4:
1203                 return ff_layout_async_handle_error_v4(task, state, clp,
1204                                                        lseg, idx);
1205         default:
1206                 /* should never happen */
1207                 WARN_ON_ONCE(1);
1208                 return 0;
1209         }
1210 }
1211
1212 static void ff_layout_io_track_ds_error(struct pnfs_layout_segment *lseg,
1213                                         int idx, u64 offset, u64 length,
1214                                         u32 status, int opnum, int error)
1215 {
1216         struct nfs4_ff_layout_mirror *mirror;
1217         int err;
1218
1219         if (status == 0) {
1220                 switch (error) {
1221                 case -ETIMEDOUT:
1222                 case -EPFNOSUPPORT:
1223                 case -EPROTONOSUPPORT:
1224                 case -EOPNOTSUPP:
1225                 case -ECONNREFUSED:
1226                 case -ECONNRESET:
1227                 case -EHOSTDOWN:
1228                 case -EHOSTUNREACH:
1229                 case -ENETUNREACH:
1230                 case -EADDRINUSE:
1231                 case -ENOBUFS:
1232                 case -EPIPE:
1233                 case -EPERM:
1234                         status = NFS4ERR_NXIO;
1235                         break;
1236                 case -EACCES:
1237                         status = NFS4ERR_ACCESS;
1238                         break;
1239                 default:
1240                         return;
1241                 }
1242         }
1243
1244         switch (status) {
1245         case NFS4ERR_DELAY:
1246         case NFS4ERR_GRACE:
1247                 return;
1248         default:
1249                 break;
1250         }
1251
1252         mirror = FF_LAYOUT_COMP(lseg, idx);
1253         err = ff_layout_track_ds_error(FF_LAYOUT_FROM_HDR(lseg->pls_layout),
1254                                        mirror, offset, length, status, opnum,
1255                                        GFP_NOIO);
1256         pnfs_error_mark_layout_for_return(lseg->pls_layout->plh_inode, lseg);
1257         dprintk("%s: err %d op %d status %u\n", __func__, err, opnum, status);
1258 }
1259
1260 /* NFS_PROTO call done callback routines */
1261 static int ff_layout_read_done_cb(struct rpc_task *task,
1262                                 struct nfs_pgio_header *hdr)
1263 {
1264         int err;
1265
1266         trace_nfs4_pnfs_read(hdr, task->tk_status);
1267         if (task->tk_status < 0)
1268                 ff_layout_io_track_ds_error(hdr->lseg, hdr->pgio_mirror_idx,
1269                                             hdr->args.offset, hdr->args.count,
1270                                             hdr->res.op_status, OP_READ,
1271                                             task->tk_status);
1272         err = ff_layout_async_handle_error(task, hdr->args.context->state,
1273                                            hdr->ds_clp, hdr->lseg,
1274                                            hdr->pgio_mirror_idx);
1275
1276         switch (err) {
1277         case -NFS4ERR_RESET_TO_PNFS:
1278                 if (ff_layout_choose_best_ds_for_read(hdr->lseg,
1279                                         hdr->pgio_mirror_idx + 1,
1280                                         &hdr->pgio_mirror_idx))
1281                         goto out_eagain;
1282                 ff_layout_read_record_layoutstats_done(task, hdr);
1283                 pnfs_read_resend_pnfs(hdr);
1284                 return task->tk_status;
1285         case -NFS4ERR_RESET_TO_MDS:
1286                 ff_layout_reset_read(hdr);
1287                 return task->tk_status;
1288         case -EAGAIN:
1289                 goto out_eagain;
1290         }
1291
1292         return 0;
1293 out_eagain:
1294         rpc_restart_call_prepare(task);
1295         return -EAGAIN;
1296 }
1297
1298 static bool
1299 ff_layout_need_layoutcommit(struct pnfs_layout_segment *lseg)
1300 {
1301         return !(FF_LAYOUT_LSEG(lseg)->flags & FF_FLAGS_NO_LAYOUTCOMMIT);
1302 }
1303
1304 /*
1305  * We reference the rpc_cred of the first WRITE that triggers the need for
1306  * a LAYOUTCOMMIT, and use it to send the layoutcommit compound.
1307  * rfc5661 is not clear about which credential should be used.
1308  *
1309  * Flexlayout client should treat DS replied FILE_SYNC as DATA_SYNC, so
1310  * to follow http://www.rfc-editor.org/errata_search.php?rfc=5661&eid=2751
1311  * we always send layoutcommit after DS writes.
1312  */
1313 static void
1314 ff_layout_set_layoutcommit(struct inode *inode,
1315                 struct pnfs_layout_segment *lseg,
1316                 loff_t end_offset)
1317 {
1318         if (!ff_layout_need_layoutcommit(lseg))
1319                 return;
1320
1321         pnfs_set_layoutcommit(inode, lseg, end_offset);
1322         dprintk("%s inode %lu pls_end_pos %llu\n", __func__, inode->i_ino,
1323                 (unsigned long long) NFS_I(inode)->layout->plh_lwb);
1324 }
1325
1326 static bool
1327 ff_layout_device_unavailable(struct pnfs_layout_segment *lseg, int idx)
1328 {
1329         /* No mirroring for now */
1330         struct nfs4_deviceid_node *node = FF_LAYOUT_DEVID_NODE(lseg, idx);
1331
1332         return ff_layout_test_devid_unavailable(node);
1333 }
1334
1335 static void ff_layout_read_record_layoutstats_start(struct rpc_task *task,
1336                 struct nfs_pgio_header *hdr)
1337 {
1338         if (test_and_set_bit(NFS_IOHDR_STAT, &hdr->flags))
1339                 return;
1340         nfs4_ff_layout_stat_io_start_read(hdr->inode,
1341                         FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
1342                         hdr->args.count,
1343                         task->tk_start);
1344 }
1345
1346 static void ff_layout_read_record_layoutstats_done(struct rpc_task *task,
1347                 struct nfs_pgio_header *hdr)
1348 {
1349         if (!test_and_clear_bit(NFS_IOHDR_STAT, &hdr->flags))
1350                 return;
1351         nfs4_ff_layout_stat_io_end_read(task,
1352                         FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
1353                         hdr->args.count,
1354                         hdr->res.count);
1355 }
1356
1357 static int ff_layout_read_prepare_common(struct rpc_task *task,
1358                                          struct nfs_pgio_header *hdr)
1359 {
1360         if (unlikely(test_bit(NFS_CONTEXT_BAD, &hdr->args.context->flags))) {
1361                 rpc_exit(task, -EIO);
1362                 return -EIO;
1363         }
1364         if (ff_layout_device_unavailable(hdr->lseg, hdr->pgio_mirror_idx)) {
1365                 rpc_exit(task, -EHOSTDOWN);
1366                 return -EAGAIN;
1367         }
1368
1369         ff_layout_read_record_layoutstats_start(task, hdr);
1370         return 0;
1371 }
1372
1373 /*
1374  * Call ops for the async read/write cases
1375  * In the case of dense layouts, the offset needs to be reset to its
1376  * original value.
1377  */
1378 static void ff_layout_read_prepare_v3(struct rpc_task *task, void *data)
1379 {
1380         struct nfs_pgio_header *hdr = data;
1381
1382         if (ff_layout_read_prepare_common(task, hdr))
1383                 return;
1384
1385         rpc_call_start(task);
1386 }
1387
1388 static void ff_layout_read_prepare_v4(struct rpc_task *task, void *data)
1389 {
1390         struct nfs_pgio_header *hdr = data;
1391
1392         if (nfs4_setup_sequence(hdr->ds_clp,
1393                                 &hdr->args.seq_args,
1394                                 &hdr->res.seq_res,
1395                                 task))
1396                 return;
1397
1398         if (ff_layout_read_prepare_common(task, hdr))
1399                 return;
1400
1401         if (nfs4_set_rw_stateid(&hdr->args.stateid, hdr->args.context,
1402                         hdr->args.lock_context, FMODE_READ) == -EIO)
1403                 rpc_exit(task, -EIO); /* lost lock, terminate I/O */
1404 }
1405
1406 static void ff_layout_read_call_done(struct rpc_task *task, void *data)
1407 {
1408         struct nfs_pgio_header *hdr = data;
1409
1410         dprintk("--> %s task->tk_status %d\n", __func__, task->tk_status);
1411
1412         if (test_bit(NFS_IOHDR_REDO, &hdr->flags) &&
1413             task->tk_status == 0) {
1414                 nfs4_sequence_done(task, &hdr->res.seq_res);
1415                 return;
1416         }
1417
1418         /* Note this may cause RPC to be resent */
1419         hdr->mds_ops->rpc_call_done(task, hdr);
1420 }
1421
1422 static void ff_layout_read_count_stats(struct rpc_task *task, void *data)
1423 {
1424         struct nfs_pgio_header *hdr = data;
1425
1426         ff_layout_read_record_layoutstats_done(task, hdr);
1427         rpc_count_iostats_metrics(task,
1428             &NFS_CLIENT(hdr->inode)->cl_metrics[NFSPROC4_CLNT_READ]);
1429 }
1430
1431 static void ff_layout_read_release(void *data)
1432 {
1433         struct nfs_pgio_header *hdr = data;
1434
1435         ff_layout_read_record_layoutstats_done(&hdr->task, hdr);
1436         pnfs_generic_rw_release(data);
1437 }
1438
1439
1440 static int ff_layout_write_done_cb(struct rpc_task *task,
1441                                 struct nfs_pgio_header *hdr)
1442 {
1443         loff_t end_offs = 0;
1444         int err;
1445
1446         trace_nfs4_pnfs_write(hdr, task->tk_status);
1447         if (task->tk_status < 0)
1448                 ff_layout_io_track_ds_error(hdr->lseg, hdr->pgio_mirror_idx,
1449                                             hdr->args.offset, hdr->args.count,
1450                                             hdr->res.op_status, OP_WRITE,
1451                                             task->tk_status);
1452         err = ff_layout_async_handle_error(task, hdr->args.context->state,
1453                                            hdr->ds_clp, hdr->lseg,
1454                                            hdr->pgio_mirror_idx);
1455
1456         switch (err) {
1457         case -NFS4ERR_RESET_TO_PNFS:
1458                 ff_layout_reset_write(hdr, true);
1459                 return task->tk_status;
1460         case -NFS4ERR_RESET_TO_MDS:
1461                 ff_layout_reset_write(hdr, false);
1462                 return task->tk_status;
1463         case -EAGAIN:
1464                 return -EAGAIN;
1465         }
1466
1467         if (hdr->res.verf->committed == NFS_FILE_SYNC ||
1468             hdr->res.verf->committed == NFS_DATA_SYNC)
1469                 end_offs = hdr->mds_offset + (loff_t)hdr->res.count;
1470
1471         /* Note: if the write is unstable, don't set end_offs until commit */
1472         ff_layout_set_layoutcommit(hdr->inode, hdr->lseg, end_offs);
1473
1474         /* zero out fattr since we don't care DS attr at all */
1475         hdr->fattr.valid = 0;
1476         if (task->tk_status >= 0)
1477                 nfs_writeback_update_inode(hdr);
1478
1479         return 0;
1480 }
1481
1482 static int ff_layout_commit_done_cb(struct rpc_task *task,
1483                                      struct nfs_commit_data *data)
1484 {
1485         int err;
1486
1487         trace_nfs4_pnfs_commit_ds(data, task->tk_status);
1488         if (task->tk_status < 0)
1489                 ff_layout_io_track_ds_error(data->lseg, data->ds_commit_index,
1490                                             data->args.offset, data->args.count,
1491                                             data->res.op_status, OP_COMMIT,
1492                                             task->tk_status);
1493         err = ff_layout_async_handle_error(task, NULL, data->ds_clp,
1494                                            data->lseg, data->ds_commit_index);
1495
1496         switch (err) {
1497         case -NFS4ERR_RESET_TO_PNFS:
1498                 pnfs_generic_prepare_to_resend_writes(data);
1499                 return -EAGAIN;
1500         case -NFS4ERR_RESET_TO_MDS:
1501                 pnfs_generic_prepare_to_resend_writes(data);
1502                 return -EAGAIN;
1503         case -EAGAIN:
1504                 rpc_restart_call_prepare(task);
1505                 return -EAGAIN;
1506         }
1507
1508         ff_layout_set_layoutcommit(data->inode, data->lseg, data->lwb);
1509
1510         return 0;
1511 }
1512
1513 static void ff_layout_write_record_layoutstats_start(struct rpc_task *task,
1514                 struct nfs_pgio_header *hdr)
1515 {
1516         if (test_and_set_bit(NFS_IOHDR_STAT, &hdr->flags))
1517                 return;
1518         nfs4_ff_layout_stat_io_start_write(hdr->inode,
1519                         FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
1520                         hdr->args.count,
1521                         task->tk_start);
1522 }
1523
1524 static void ff_layout_write_record_layoutstats_done(struct rpc_task *task,
1525                 struct nfs_pgio_header *hdr)
1526 {
1527         if (!test_and_clear_bit(NFS_IOHDR_STAT, &hdr->flags))
1528                 return;
1529         nfs4_ff_layout_stat_io_end_write(task,
1530                         FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
1531                         hdr->args.count, hdr->res.count,
1532                         hdr->res.verf->committed);
1533 }
1534
1535 static int ff_layout_write_prepare_common(struct rpc_task *task,
1536                                           struct nfs_pgio_header *hdr)
1537 {
1538         if (unlikely(test_bit(NFS_CONTEXT_BAD, &hdr->args.context->flags))) {
1539                 rpc_exit(task, -EIO);
1540                 return -EIO;
1541         }
1542
1543         if (ff_layout_device_unavailable(hdr->lseg, hdr->pgio_mirror_idx)) {
1544                 rpc_exit(task, -EHOSTDOWN);
1545                 return -EAGAIN;
1546         }
1547
1548         ff_layout_write_record_layoutstats_start(task, hdr);
1549         return 0;
1550 }
1551
1552 static void ff_layout_write_prepare_v3(struct rpc_task *task, void *data)
1553 {
1554         struct nfs_pgio_header *hdr = data;
1555
1556         if (ff_layout_write_prepare_common(task, hdr))
1557                 return;
1558
1559         rpc_call_start(task);
1560 }
1561
1562 static void ff_layout_write_prepare_v4(struct rpc_task *task, void *data)
1563 {
1564         struct nfs_pgio_header *hdr = data;
1565
1566         if (nfs4_setup_sequence(hdr->ds_clp,
1567                                 &hdr->args.seq_args,
1568                                 &hdr->res.seq_res,
1569                                 task))
1570                 return;
1571
1572         if (ff_layout_write_prepare_common(task, hdr))
1573                 return;
1574
1575         if (nfs4_set_rw_stateid(&hdr->args.stateid, hdr->args.context,
1576                         hdr->args.lock_context, FMODE_WRITE) == -EIO)
1577                 rpc_exit(task, -EIO); /* lost lock, terminate I/O */
1578 }
1579
1580 static void ff_layout_write_call_done(struct rpc_task *task, void *data)
1581 {
1582         struct nfs_pgio_header *hdr = data;
1583
1584         if (test_bit(NFS_IOHDR_REDO, &hdr->flags) &&
1585             task->tk_status == 0) {
1586                 nfs4_sequence_done(task, &hdr->res.seq_res);
1587                 return;
1588         }
1589
1590         /* Note this may cause RPC to be resent */
1591         hdr->mds_ops->rpc_call_done(task, hdr);
1592 }
1593
1594 static void ff_layout_write_count_stats(struct rpc_task *task, void *data)
1595 {
1596         struct nfs_pgio_header *hdr = data;
1597
1598         ff_layout_write_record_layoutstats_done(task, hdr);
1599         rpc_count_iostats_metrics(task,
1600             &NFS_CLIENT(hdr->inode)->cl_metrics[NFSPROC4_CLNT_WRITE]);
1601 }
1602
1603 static void ff_layout_write_release(void *data)
1604 {
1605         struct nfs_pgio_header *hdr = data;
1606
1607         ff_layout_write_record_layoutstats_done(&hdr->task, hdr);
1608         pnfs_generic_rw_release(data);
1609 }
1610
1611 static void ff_layout_commit_record_layoutstats_start(struct rpc_task *task,
1612                 struct nfs_commit_data *cdata)
1613 {
1614         if (test_and_set_bit(NFS_IOHDR_STAT, &cdata->flags))
1615                 return;
1616         nfs4_ff_layout_stat_io_start_write(cdata->inode,
1617                         FF_LAYOUT_COMP(cdata->lseg, cdata->ds_commit_index),
1618                         0, task->tk_start);
1619 }
1620
1621 static void ff_layout_commit_record_layoutstats_done(struct rpc_task *task,
1622                 struct nfs_commit_data *cdata)
1623 {
1624         struct nfs_page *req;
1625         __u64 count = 0;
1626
1627         if (!test_and_clear_bit(NFS_IOHDR_STAT, &cdata->flags))
1628                 return;
1629
1630         if (task->tk_status == 0) {
1631                 list_for_each_entry(req, &cdata->pages, wb_list)
1632                         count += req->wb_bytes;
1633         }
1634         nfs4_ff_layout_stat_io_end_write(task,
1635                         FF_LAYOUT_COMP(cdata->lseg, cdata->ds_commit_index),
1636                         count, count, NFS_FILE_SYNC);
1637 }
1638
1639 static void ff_layout_commit_prepare_common(struct rpc_task *task,
1640                 struct nfs_commit_data *cdata)
1641 {
1642         ff_layout_commit_record_layoutstats_start(task, cdata);
1643 }
1644
1645 static void ff_layout_commit_prepare_v3(struct rpc_task *task, void *data)
1646 {
1647         ff_layout_commit_prepare_common(task, data);
1648         rpc_call_start(task);
1649 }
1650
1651 static void ff_layout_commit_prepare_v4(struct rpc_task *task, void *data)
1652 {
1653         struct nfs_commit_data *wdata = data;
1654
1655         if (nfs4_setup_sequence(wdata->ds_clp,
1656                                 &wdata->args.seq_args,
1657                                 &wdata->res.seq_res,
1658                                 task))
1659                 return;
1660         ff_layout_commit_prepare_common(task, data);
1661 }
1662
1663 static void ff_layout_commit_done(struct rpc_task *task, void *data)
1664 {
1665         pnfs_generic_write_commit_done(task, data);
1666 }
1667
1668 static void ff_layout_commit_count_stats(struct rpc_task *task, void *data)
1669 {
1670         struct nfs_commit_data *cdata = data;
1671
1672         ff_layout_commit_record_layoutstats_done(task, cdata);
1673         rpc_count_iostats_metrics(task,
1674             &NFS_CLIENT(cdata->inode)->cl_metrics[NFSPROC4_CLNT_COMMIT]);
1675 }
1676
1677 static void ff_layout_commit_release(void *data)
1678 {
1679         struct nfs_commit_data *cdata = data;
1680
1681         ff_layout_commit_record_layoutstats_done(&cdata->task, cdata);
1682         pnfs_generic_commit_release(data);
1683 }
1684
1685 static const struct rpc_call_ops ff_layout_read_call_ops_v3 = {
1686         .rpc_call_prepare = ff_layout_read_prepare_v3,
1687         .rpc_call_done = ff_layout_read_call_done,
1688         .rpc_count_stats = ff_layout_read_count_stats,
1689         .rpc_release = ff_layout_read_release,
1690 };
1691
1692 static const struct rpc_call_ops ff_layout_read_call_ops_v4 = {
1693         .rpc_call_prepare = ff_layout_read_prepare_v4,
1694         .rpc_call_done = ff_layout_read_call_done,
1695         .rpc_count_stats = ff_layout_read_count_stats,
1696         .rpc_release = ff_layout_read_release,
1697 };
1698
1699 static const struct rpc_call_ops ff_layout_write_call_ops_v3 = {
1700         .rpc_call_prepare = ff_layout_write_prepare_v3,
1701         .rpc_call_done = ff_layout_write_call_done,
1702         .rpc_count_stats = ff_layout_write_count_stats,
1703         .rpc_release = ff_layout_write_release,
1704 };
1705
1706 static const struct rpc_call_ops ff_layout_write_call_ops_v4 = {
1707         .rpc_call_prepare = ff_layout_write_prepare_v4,
1708         .rpc_call_done = ff_layout_write_call_done,
1709         .rpc_count_stats = ff_layout_write_count_stats,
1710         .rpc_release = ff_layout_write_release,
1711 };
1712
1713 static const struct rpc_call_ops ff_layout_commit_call_ops_v3 = {
1714         .rpc_call_prepare = ff_layout_commit_prepare_v3,
1715         .rpc_call_done = ff_layout_commit_done,
1716         .rpc_count_stats = ff_layout_commit_count_stats,
1717         .rpc_release = ff_layout_commit_release,
1718 };
1719
1720 static const struct rpc_call_ops ff_layout_commit_call_ops_v4 = {
1721         .rpc_call_prepare = ff_layout_commit_prepare_v4,
1722         .rpc_call_done = ff_layout_commit_done,
1723         .rpc_count_stats = ff_layout_commit_count_stats,
1724         .rpc_release = ff_layout_commit_release,
1725 };
1726
1727 static enum pnfs_try_status
1728 ff_layout_read_pagelist(struct nfs_pgio_header *hdr)
1729 {
1730         struct pnfs_layout_segment *lseg = hdr->lseg;
1731         struct nfs4_pnfs_ds *ds;
1732         struct rpc_clnt *ds_clnt;
1733         struct rpc_cred *ds_cred;
1734         loff_t offset = hdr->args.offset;
1735         u32 idx = hdr->pgio_mirror_idx;
1736         int vers;
1737         struct nfs_fh *fh;
1738
1739         dprintk("--> %s ino %lu pgbase %u req %zu@%llu\n",
1740                 __func__, hdr->inode->i_ino,
1741                 hdr->args.pgbase, (size_t)hdr->args.count, offset);
1742
1743         ds = nfs4_ff_layout_prepare_ds(lseg, idx, false);
1744         if (!ds)
1745                 goto out_failed;
1746
1747         ds_clnt = nfs4_ff_find_or_create_ds_client(lseg, idx, ds->ds_clp,
1748                                                    hdr->inode);
1749         if (IS_ERR(ds_clnt))
1750                 goto out_failed;
1751
1752         ds_cred = ff_layout_get_ds_cred(lseg, idx, hdr->cred);
1753         if (!ds_cred)
1754                 goto out_failed;
1755
1756         vers = nfs4_ff_layout_ds_version(lseg, idx);
1757
1758         dprintk("%s USE DS: %s cl_count %d vers %d\n", __func__,
1759                 ds->ds_remotestr, atomic_read(&ds->ds_clp->cl_count), vers);
1760
1761         hdr->pgio_done_cb = ff_layout_read_done_cb;
1762         atomic_inc(&ds->ds_clp->cl_count);
1763         hdr->ds_clp = ds->ds_clp;
1764         fh = nfs4_ff_layout_select_ds_fh(lseg, idx);
1765         if (fh)
1766                 hdr->args.fh = fh;
1767         /*
1768          * Note that if we ever decide to split across DSes,
1769          * then we may need to handle dense-like offsets.
1770          */
1771         hdr->args.offset = offset;
1772         hdr->mds_offset = offset;
1773
1774         /* Perform an asynchronous read to ds */
1775         nfs_initiate_pgio(ds_clnt, hdr, ds_cred, ds->ds_clp->rpc_ops,
1776                           vers == 3 ? &ff_layout_read_call_ops_v3 :
1777                                       &ff_layout_read_call_ops_v4,
1778                           0, RPC_TASK_SOFTCONN);
1779         put_rpccred(ds_cred);
1780         return PNFS_ATTEMPTED;
1781
1782 out_failed:
1783         if (ff_layout_avoid_mds_available_ds(lseg))
1784                 return PNFS_TRY_AGAIN;
1785         return PNFS_NOT_ATTEMPTED;
1786 }
1787
1788 /* Perform async writes. */
1789 static enum pnfs_try_status
1790 ff_layout_write_pagelist(struct nfs_pgio_header *hdr, int sync)
1791 {
1792         struct pnfs_layout_segment *lseg = hdr->lseg;
1793         struct nfs4_pnfs_ds *ds;
1794         struct rpc_clnt *ds_clnt;
1795         struct rpc_cred *ds_cred;
1796         loff_t offset = hdr->args.offset;
1797         int vers;
1798         struct nfs_fh *fh;
1799         int idx = hdr->pgio_mirror_idx;
1800
1801         ds = nfs4_ff_layout_prepare_ds(lseg, idx, true);
1802         if (!ds)
1803                 return PNFS_NOT_ATTEMPTED;
1804
1805         ds_clnt = nfs4_ff_find_or_create_ds_client(lseg, idx, ds->ds_clp,
1806                                                    hdr->inode);
1807         if (IS_ERR(ds_clnt))
1808                 return PNFS_NOT_ATTEMPTED;
1809
1810         ds_cred = ff_layout_get_ds_cred(lseg, idx, hdr->cred);
1811         if (!ds_cred)
1812                 return PNFS_NOT_ATTEMPTED;
1813
1814         vers = nfs4_ff_layout_ds_version(lseg, idx);
1815
1816         dprintk("%s ino %lu sync %d req %zu@%llu DS: %s cl_count %d vers %d\n",
1817                 __func__, hdr->inode->i_ino, sync, (size_t) hdr->args.count,
1818                 offset, ds->ds_remotestr, atomic_read(&ds->ds_clp->cl_count),
1819                 vers);
1820
1821         hdr->pgio_done_cb = ff_layout_write_done_cb;
1822         atomic_inc(&ds->ds_clp->cl_count);
1823         hdr->ds_clp = ds->ds_clp;
1824         hdr->ds_commit_idx = idx;
1825         fh = nfs4_ff_layout_select_ds_fh(lseg, idx);
1826         if (fh)
1827                 hdr->args.fh = fh;
1828
1829         /*
1830          * Note that if we ever decide to split across DSes,
1831          * then we may need to handle dense-like offsets.
1832          */
1833         hdr->args.offset = offset;
1834
1835         /* Perform an asynchronous write */
1836         nfs_initiate_pgio(ds_clnt, hdr, ds_cred, ds->ds_clp->rpc_ops,
1837                           vers == 3 ? &ff_layout_write_call_ops_v3 :
1838                                       &ff_layout_write_call_ops_v4,
1839                           sync, RPC_TASK_SOFTCONN);
1840         put_rpccred(ds_cred);
1841         return PNFS_ATTEMPTED;
1842 }
1843
1844 static u32 calc_ds_index_from_commit(struct pnfs_layout_segment *lseg, u32 i)
1845 {
1846         return i;
1847 }
1848
1849 static struct nfs_fh *
1850 select_ds_fh_from_commit(struct pnfs_layout_segment *lseg, u32 i)
1851 {
1852         struct nfs4_ff_layout_segment *flseg = FF_LAYOUT_LSEG(lseg);
1853
1854         /* FIXME: Assume that there is only one NFS version available
1855          * for the DS.
1856          */
1857         return &flseg->mirror_array[i]->fh_versions[0];
1858 }
1859
1860 static int ff_layout_initiate_commit(struct nfs_commit_data *data, int how)
1861 {
1862         struct pnfs_layout_segment *lseg = data->lseg;
1863         struct nfs4_pnfs_ds *ds;
1864         struct rpc_clnt *ds_clnt;
1865         struct rpc_cred *ds_cred;
1866         u32 idx;
1867         int vers, ret;
1868         struct nfs_fh *fh;
1869
1870         idx = calc_ds_index_from_commit(lseg, data->ds_commit_index);
1871         ds = nfs4_ff_layout_prepare_ds(lseg, idx, true);
1872         if (!ds)
1873                 goto out_err;
1874
1875         ds_clnt = nfs4_ff_find_or_create_ds_client(lseg, idx, ds->ds_clp,
1876                                                    data->inode);
1877         if (IS_ERR(ds_clnt))
1878                 goto out_err;
1879
1880         ds_cred = ff_layout_get_ds_cred(lseg, idx, data->cred);
1881         if (!ds_cred)
1882                 goto out_err;
1883
1884         vers = nfs4_ff_layout_ds_version(lseg, idx);
1885
1886         dprintk("%s ino %lu, how %d cl_count %d vers %d\n", __func__,
1887                 data->inode->i_ino, how, atomic_read(&ds->ds_clp->cl_count),
1888                 vers);
1889         data->commit_done_cb = ff_layout_commit_done_cb;
1890         data->cred = ds_cred;
1891         atomic_inc(&ds->ds_clp->cl_count);
1892         data->ds_clp = ds->ds_clp;
1893         fh = select_ds_fh_from_commit(lseg, data->ds_commit_index);
1894         if (fh)
1895                 data->args.fh = fh;
1896
1897         ret = nfs_initiate_commit(ds_clnt, data, ds->ds_clp->rpc_ops,
1898                                    vers == 3 ? &ff_layout_commit_call_ops_v3 :
1899                                                &ff_layout_commit_call_ops_v4,
1900                                    how, RPC_TASK_SOFTCONN);
1901         put_rpccred(ds_cred);
1902         return ret;
1903 out_err:
1904         pnfs_generic_prepare_to_resend_writes(data);
1905         pnfs_generic_commit_release(data);
1906         return -EAGAIN;
1907 }
1908
1909 static int
1910 ff_layout_commit_pagelist(struct inode *inode, struct list_head *mds_pages,
1911                            int how, struct nfs_commit_info *cinfo)
1912 {
1913         return pnfs_generic_commit_pagelist(inode, mds_pages, how, cinfo,
1914                                             ff_layout_initiate_commit);
1915 }
1916
1917 static struct pnfs_ds_commit_info *
1918 ff_layout_get_ds_info(struct inode *inode)
1919 {
1920         struct pnfs_layout_hdr *layout = NFS_I(inode)->layout;
1921
1922         if (layout == NULL)
1923                 return NULL;
1924
1925         return &FF_LAYOUT_FROM_HDR(layout)->commit_info;
1926 }
1927
1928 static void
1929 ff_layout_free_deviceid_node(struct nfs4_deviceid_node *d)
1930 {
1931         nfs4_ff_layout_free_deviceid(container_of(d, struct nfs4_ff_layout_ds,
1932                                                   id_node));
1933 }
1934
1935 static int ff_layout_encode_ioerr(struct xdr_stream *xdr,
1936                                   const struct nfs4_layoutreturn_args *args,
1937                                   const struct nfs4_flexfile_layoutreturn_args *ff_args)
1938 {
1939         __be32 *start;
1940
1941         start = xdr_reserve_space(xdr, 4);
1942         if (unlikely(!start))
1943                 return -E2BIG;
1944
1945         *start = cpu_to_be32(ff_args->num_errors);
1946         /* This assume we always return _ALL_ layouts */
1947         return ff_layout_encode_ds_ioerr(xdr, &ff_args->errors);
1948 }
1949
1950 static void
1951 encode_opaque_fixed(struct xdr_stream *xdr, const void *buf, size_t len)
1952 {
1953         WARN_ON_ONCE(xdr_stream_encode_opaque_fixed(xdr, buf, len) < 0);
1954 }
1955
1956 static void
1957 ff_layout_encode_ff_iostat_head(struct xdr_stream *xdr,
1958                             const nfs4_stateid *stateid,
1959                             const struct nfs42_layoutstat_devinfo *devinfo)
1960 {
1961         __be32 *p;
1962
1963         p = xdr_reserve_space(xdr, 8 + 8);
1964         p = xdr_encode_hyper(p, devinfo->offset);
1965         p = xdr_encode_hyper(p, devinfo->length);
1966         encode_opaque_fixed(xdr, stateid->data, NFS4_STATEID_SIZE);
1967         p = xdr_reserve_space(xdr, 4*8);
1968         p = xdr_encode_hyper(p, devinfo->read_count);
1969         p = xdr_encode_hyper(p, devinfo->read_bytes);
1970         p = xdr_encode_hyper(p, devinfo->write_count);
1971         p = xdr_encode_hyper(p, devinfo->write_bytes);
1972         encode_opaque_fixed(xdr, devinfo->dev_id.data, NFS4_DEVICEID4_SIZE);
1973 }
1974
1975 static void
1976 ff_layout_encode_ff_iostat(struct xdr_stream *xdr,
1977                             const nfs4_stateid *stateid,
1978                             const struct nfs42_layoutstat_devinfo *devinfo)
1979 {
1980         ff_layout_encode_ff_iostat_head(xdr, stateid, devinfo);
1981         ff_layout_encode_ff_layoutupdate(xdr, devinfo,
1982                         devinfo->ld_private.data);
1983 }
1984
1985 /* report nothing for now */
1986 static void ff_layout_encode_iostats_array(struct xdr_stream *xdr,
1987                 const struct nfs4_layoutreturn_args *args,
1988                 struct nfs4_flexfile_layoutreturn_args *ff_args)
1989 {
1990         __be32 *p;
1991         int i;
1992
1993         p = xdr_reserve_space(xdr, 4);
1994         *p = cpu_to_be32(ff_args->num_dev);
1995         for (i = 0; i < ff_args->num_dev; i++)
1996                 ff_layout_encode_ff_iostat(xdr,
1997                                 &args->layout->plh_stateid,
1998                                 &ff_args->devinfo[i]);
1999 }
2000
2001 static void
2002 ff_layout_free_iostats_array(struct nfs42_layoutstat_devinfo *devinfo,
2003                 unsigned int num_entries)
2004 {
2005         unsigned int i;
2006
2007         for (i = 0; i < num_entries; i++) {
2008                 if (!devinfo[i].ld_private.ops)
2009                         continue;
2010                 if (!devinfo[i].ld_private.ops->free)
2011                         continue;
2012                 devinfo[i].ld_private.ops->free(&devinfo[i].ld_private);
2013         }
2014 }
2015
2016 static struct nfs4_deviceid_node *
2017 ff_layout_alloc_deviceid_node(struct nfs_server *server,
2018                               struct pnfs_device *pdev, gfp_t gfp_flags)
2019 {
2020         struct nfs4_ff_layout_ds *dsaddr;
2021
2022         dsaddr = nfs4_ff_alloc_deviceid_node(server, pdev, gfp_flags);
2023         if (!dsaddr)
2024                 return NULL;
2025         return &dsaddr->id_node;
2026 }
2027
2028 static void
2029 ff_layout_encode_layoutreturn(struct xdr_stream *xdr,
2030                 const void *voidargs,
2031                 const struct nfs4_xdr_opaque_data *ff_opaque)
2032 {
2033         const struct nfs4_layoutreturn_args *args = voidargs;
2034         struct nfs4_flexfile_layoutreturn_args *ff_args = ff_opaque->data;
2035         struct xdr_buf tmp_buf = {
2036                 .head = {
2037                         [0] = {
2038                                 .iov_base = page_address(ff_args->pages[0]),
2039                         },
2040                 },
2041                 .buflen = PAGE_SIZE,
2042         };
2043         struct xdr_stream tmp_xdr;
2044         __be32 *start;
2045
2046         dprintk("%s: Begin\n", __func__);
2047
2048         xdr_init_encode(&tmp_xdr, &tmp_buf, NULL);
2049
2050         ff_layout_encode_ioerr(&tmp_xdr, args, ff_args);
2051         ff_layout_encode_iostats_array(&tmp_xdr, args, ff_args);
2052
2053         start = xdr_reserve_space(xdr, 4);
2054         *start = cpu_to_be32(tmp_buf.len);
2055         xdr_write_pages(xdr, ff_args->pages, 0, tmp_buf.len);
2056
2057         dprintk("%s: Return\n", __func__);
2058 }
2059
2060 static void
2061 ff_layout_free_layoutreturn(struct nfs4_xdr_opaque_data *args)
2062 {
2063         struct nfs4_flexfile_layoutreturn_args *ff_args;
2064
2065         if (!args->data)
2066                 return;
2067         ff_args = args->data;
2068         args->data = NULL;
2069
2070         ff_layout_free_ds_ioerr(&ff_args->errors);
2071         ff_layout_free_iostats_array(ff_args->devinfo, ff_args->num_dev);
2072
2073         put_page(ff_args->pages[0]);
2074         kfree(ff_args);
2075 }
2076
2077 static const struct nfs4_xdr_opaque_ops layoutreturn_ops = {
2078         .encode = ff_layout_encode_layoutreturn,
2079         .free = ff_layout_free_layoutreturn,
2080 };
2081
2082 static int
2083 ff_layout_prepare_layoutreturn(struct nfs4_layoutreturn_args *args)
2084 {
2085         struct nfs4_flexfile_layoutreturn_args *ff_args;
2086         struct nfs4_flexfile_layout *ff_layout = FF_LAYOUT_FROM_HDR(args->layout);
2087
2088         ff_args = kmalloc(sizeof(*ff_args), GFP_KERNEL);
2089         if (!ff_args)
2090                 goto out_nomem;
2091         ff_args->pages[0] = alloc_page(GFP_KERNEL);
2092         if (!ff_args->pages[0])
2093                 goto out_nomem_free;
2094
2095         INIT_LIST_HEAD(&ff_args->errors);
2096         ff_args->num_errors = ff_layout_fetch_ds_ioerr(args->layout,
2097                         &args->range, &ff_args->errors,
2098                         FF_LAYOUTRETURN_MAXERR);
2099
2100         spin_lock(&args->inode->i_lock);
2101         ff_args->num_dev = ff_layout_mirror_prepare_stats(&ff_layout->generic_hdr,
2102                         &ff_args->devinfo[0], ARRAY_SIZE(ff_args->devinfo));
2103         spin_unlock(&args->inode->i_lock);
2104
2105         args->ld_private->ops = &layoutreturn_ops;
2106         args->ld_private->data = ff_args;
2107         return 0;
2108 out_nomem_free:
2109         kfree(ff_args);
2110 out_nomem:
2111         return -ENOMEM;
2112 }
2113
2114 static int
2115 ff_layout_ntop4(const struct sockaddr *sap, char *buf, const size_t buflen)
2116 {
2117         const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
2118
2119         return snprintf(buf, buflen, "%pI4", &sin->sin_addr);
2120 }
2121
2122 static size_t
2123 ff_layout_ntop6_noscopeid(const struct sockaddr *sap, char *buf,
2124                           const int buflen)
2125 {
2126         const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
2127         const struct in6_addr *addr = &sin6->sin6_addr;
2128
2129         /*
2130          * RFC 4291, Section 2.2.2
2131          *
2132          * Shorthanded ANY address
2133          */
2134         if (ipv6_addr_any(addr))
2135                 return snprintf(buf, buflen, "::");
2136
2137         /*
2138          * RFC 4291, Section 2.2.2
2139          *
2140          * Shorthanded loopback address
2141          */
2142         if (ipv6_addr_loopback(addr))
2143                 return snprintf(buf, buflen, "::1");
2144
2145         /*
2146          * RFC 4291, Section 2.2.3
2147          *
2148          * Special presentation address format for mapped v4
2149          * addresses.
2150          */
2151         if (ipv6_addr_v4mapped(addr))
2152                 return snprintf(buf, buflen, "::ffff:%pI4",
2153                                         &addr->s6_addr32[3]);
2154
2155         /*
2156          * RFC 4291, Section 2.2.1
2157          */
2158         return snprintf(buf, buflen, "%pI6c", addr);
2159 }
2160
2161 /* Derived from rpc_sockaddr2uaddr */
2162 static void
2163 ff_layout_encode_netaddr(struct xdr_stream *xdr, struct nfs4_pnfs_ds_addr *da)
2164 {
2165         struct sockaddr *sap = (struct sockaddr *)&da->da_addr;
2166         char portbuf[RPCBIND_MAXUADDRPLEN];
2167         char addrbuf[RPCBIND_MAXUADDRLEN];
2168         char *netid;
2169         unsigned short port;
2170         int len, netid_len;
2171         __be32 *p;
2172
2173         switch (sap->sa_family) {
2174         case AF_INET:
2175                 if (ff_layout_ntop4(sap, addrbuf, sizeof(addrbuf)) == 0)
2176                         return;
2177                 port = ntohs(((struct sockaddr_in *)sap)->sin_port);
2178                 netid = "tcp";
2179                 netid_len = 3;
2180                 break;
2181         case AF_INET6:
2182                 if (ff_layout_ntop6_noscopeid(sap, addrbuf, sizeof(addrbuf)) == 0)
2183                         return;
2184                 port = ntohs(((struct sockaddr_in6 *)sap)->sin6_port);
2185                 netid = "tcp6";
2186                 netid_len = 4;
2187                 break;
2188         default:
2189                 /* we only support tcp and tcp6 */
2190                 WARN_ON_ONCE(1);
2191                 return;
2192         }
2193
2194         snprintf(portbuf, sizeof(portbuf), ".%u.%u", port >> 8, port & 0xff);
2195         len = strlcat(addrbuf, portbuf, sizeof(addrbuf));
2196
2197         p = xdr_reserve_space(xdr, 4 + netid_len);
2198         xdr_encode_opaque(p, netid, netid_len);
2199
2200         p = xdr_reserve_space(xdr, 4 + len);
2201         xdr_encode_opaque(p, addrbuf, len);
2202 }
2203
2204 static void
2205 ff_layout_encode_nfstime(struct xdr_stream *xdr,
2206                          ktime_t t)
2207 {
2208         struct timespec64 ts;
2209         __be32 *p;
2210
2211         p = xdr_reserve_space(xdr, 12);
2212         ts = ktime_to_timespec64(t);
2213         p = xdr_encode_hyper(p, ts.tv_sec);
2214         *p++ = cpu_to_be32(ts.tv_nsec);
2215 }
2216
2217 static void
2218 ff_layout_encode_io_latency(struct xdr_stream *xdr,
2219                             struct nfs4_ff_io_stat *stat)
2220 {
2221         __be32 *p;
2222
2223         p = xdr_reserve_space(xdr, 5 * 8);
2224         p = xdr_encode_hyper(p, stat->ops_requested);
2225         p = xdr_encode_hyper(p, stat->bytes_requested);
2226         p = xdr_encode_hyper(p, stat->ops_completed);
2227         p = xdr_encode_hyper(p, stat->bytes_completed);
2228         p = xdr_encode_hyper(p, stat->bytes_not_delivered);
2229         ff_layout_encode_nfstime(xdr, stat->total_busy_time);
2230         ff_layout_encode_nfstime(xdr, stat->aggregate_completion_time);
2231 }
2232
2233 static void
2234 ff_layout_encode_ff_layoutupdate(struct xdr_stream *xdr,
2235                               const struct nfs42_layoutstat_devinfo *devinfo,
2236                               struct nfs4_ff_layout_mirror *mirror)
2237 {
2238         struct nfs4_pnfs_ds_addr *da;
2239         struct nfs4_pnfs_ds *ds = mirror->mirror_ds->ds;
2240         struct nfs_fh *fh = &mirror->fh_versions[0];
2241         __be32 *p;
2242
2243         da = list_first_entry(&ds->ds_addrs, struct nfs4_pnfs_ds_addr, da_node);
2244         dprintk("%s: DS %s: encoding address %s\n",
2245                 __func__, ds->ds_remotestr, da->da_remotestr);
2246         /* netaddr4 */
2247         ff_layout_encode_netaddr(xdr, da);
2248         /* nfs_fh4 */
2249         p = xdr_reserve_space(xdr, 4 + fh->size);
2250         xdr_encode_opaque(p, fh->data, fh->size);
2251         /* ff_io_latency4 read */
2252         spin_lock(&mirror->lock);
2253         ff_layout_encode_io_latency(xdr, &mirror->read_stat.io_stat);
2254         /* ff_io_latency4 write */
2255         ff_layout_encode_io_latency(xdr, &mirror->write_stat.io_stat);
2256         spin_unlock(&mirror->lock);
2257         /* nfstime4 */
2258         ff_layout_encode_nfstime(xdr, ktime_sub(ktime_get(), mirror->start_time));
2259         /* bool */
2260         p = xdr_reserve_space(xdr, 4);
2261         *p = cpu_to_be32(false);
2262 }
2263
2264 static void
2265 ff_layout_encode_layoutstats(struct xdr_stream *xdr, const void *args,
2266                              const struct nfs4_xdr_opaque_data *opaque)
2267 {
2268         struct nfs42_layoutstat_devinfo *devinfo = container_of(opaque,
2269                         struct nfs42_layoutstat_devinfo, ld_private);
2270         __be32 *start;
2271
2272         /* layoutupdate length */
2273         start = xdr_reserve_space(xdr, 4);
2274         ff_layout_encode_ff_layoutupdate(xdr, devinfo, opaque->data);
2275
2276         *start = cpu_to_be32((xdr->p - start - 1) * 4);
2277 }
2278
2279 static void
2280 ff_layout_free_layoutstats(struct nfs4_xdr_opaque_data *opaque)
2281 {
2282         struct nfs4_ff_layout_mirror *mirror = opaque->data;
2283
2284         ff_layout_put_mirror(mirror);
2285 }
2286
2287 static const struct nfs4_xdr_opaque_ops layoutstat_ops = {
2288         .encode = ff_layout_encode_layoutstats,
2289         .free   = ff_layout_free_layoutstats,
2290 };
2291
2292 static int
2293 ff_layout_mirror_prepare_stats(struct pnfs_layout_hdr *lo,
2294                                struct nfs42_layoutstat_devinfo *devinfo,
2295                                int dev_limit)
2296 {
2297         struct nfs4_flexfile_layout *ff_layout = FF_LAYOUT_FROM_HDR(lo);
2298         struct nfs4_ff_layout_mirror *mirror;
2299         struct nfs4_deviceid_node *dev;
2300         int i = 0;
2301
2302         list_for_each_entry(mirror, &ff_layout->mirrors, mirrors) {
2303                 if (i >= dev_limit)
2304                         break;
2305                 if (IS_ERR_OR_NULL(mirror->mirror_ds))
2306                         continue;
2307                 if (!test_and_clear_bit(NFS4_FF_MIRROR_STAT_AVAIL, &mirror->flags))
2308                         continue;
2309                 /* mirror refcount put in cleanup_layoutstats */
2310                 if (!atomic_inc_not_zero(&mirror->ref))
2311                         continue;
2312                 dev = &mirror->mirror_ds->id_node;
2313                 memcpy(&devinfo->dev_id, &dev->deviceid, NFS4_DEVICEID4_SIZE);
2314                 devinfo->offset = 0;
2315                 devinfo->length = NFS4_MAX_UINT64;
2316                 spin_lock(&mirror->lock);
2317                 devinfo->read_count = mirror->read_stat.io_stat.ops_completed;
2318                 devinfo->read_bytes = mirror->read_stat.io_stat.bytes_completed;
2319                 devinfo->write_count = mirror->write_stat.io_stat.ops_completed;
2320                 devinfo->write_bytes = mirror->write_stat.io_stat.bytes_completed;
2321                 spin_unlock(&mirror->lock);
2322                 devinfo->layout_type = LAYOUT_FLEX_FILES;
2323                 devinfo->ld_private.ops = &layoutstat_ops;
2324                 devinfo->ld_private.data = mirror;
2325
2326                 devinfo++;
2327                 i++;
2328         }
2329         return i;
2330 }
2331
2332 static int
2333 ff_layout_prepare_layoutstats(struct nfs42_layoutstat_args *args)
2334 {
2335         struct nfs4_flexfile_layout *ff_layout;
2336         const int dev_count = PNFS_LAYOUTSTATS_MAXDEV;
2337
2338         /* For now, send at most PNFS_LAYOUTSTATS_MAXDEV statistics */
2339         args->devinfo = kmalloc_array(dev_count, sizeof(*args->devinfo), GFP_NOIO);
2340         if (!args->devinfo)
2341                 return -ENOMEM;
2342
2343         spin_lock(&args->inode->i_lock);
2344         ff_layout = FF_LAYOUT_FROM_HDR(NFS_I(args->inode)->layout);
2345         args->num_dev = ff_layout_mirror_prepare_stats(&ff_layout->generic_hdr,
2346                         &args->devinfo[0], dev_count);
2347         spin_unlock(&args->inode->i_lock);
2348         if (!args->num_dev) {
2349                 kfree(args->devinfo);
2350                 args->devinfo = NULL;
2351                 return -ENOENT;
2352         }
2353
2354         return 0;
2355 }
2356
2357 static struct pnfs_layoutdriver_type flexfilelayout_type = {
2358         .id                     = LAYOUT_FLEX_FILES,
2359         .name                   = "LAYOUT_FLEX_FILES",
2360         .owner                  = THIS_MODULE,
2361         .alloc_layout_hdr       = ff_layout_alloc_layout_hdr,
2362         .free_layout_hdr        = ff_layout_free_layout_hdr,
2363         .alloc_lseg             = ff_layout_alloc_lseg,
2364         .free_lseg              = ff_layout_free_lseg,
2365         .add_lseg               = ff_layout_add_lseg,
2366         .pg_read_ops            = &ff_layout_pg_read_ops,
2367         .pg_write_ops           = &ff_layout_pg_write_ops,
2368         .get_ds_info            = ff_layout_get_ds_info,
2369         .free_deviceid_node     = ff_layout_free_deviceid_node,
2370         .mark_request_commit    = pnfs_layout_mark_request_commit,
2371         .clear_request_commit   = pnfs_generic_clear_request_commit,
2372         .scan_commit_lists      = pnfs_generic_scan_commit_lists,
2373         .recover_commit_reqs    = pnfs_generic_recover_commit_reqs,
2374         .commit_pagelist        = ff_layout_commit_pagelist,
2375         .read_pagelist          = ff_layout_read_pagelist,
2376         .write_pagelist         = ff_layout_write_pagelist,
2377         .alloc_deviceid_node    = ff_layout_alloc_deviceid_node,
2378         .prepare_layoutreturn   = ff_layout_prepare_layoutreturn,
2379         .sync                   = pnfs_nfs_generic_sync,
2380         .prepare_layoutstats    = ff_layout_prepare_layoutstats,
2381 };
2382
2383 static int __init nfs4flexfilelayout_init(void)
2384 {
2385         printk(KERN_INFO "%s: NFSv4 Flexfile Layout Driver Registering...\n",
2386                __func__);
2387         if (!ff_zero_group) {
2388                 ff_zero_group = groups_alloc(0);
2389                 if (!ff_zero_group)
2390                         return -ENOMEM;
2391         }
2392         return pnfs_register_layoutdriver(&flexfilelayout_type);
2393 }
2394
2395 static void __exit nfs4flexfilelayout_exit(void)
2396 {
2397         printk(KERN_INFO "%s: NFSv4 Flexfile Layout Driver Unregistering...\n",
2398                __func__);
2399         pnfs_unregister_layoutdriver(&flexfilelayout_type);
2400         if (ff_zero_group) {
2401                 put_group_info(ff_zero_group);
2402                 ff_zero_group = NULL;
2403         }
2404 }
2405
2406 MODULE_ALIAS("nfs-layouttype4-4");
2407
2408 MODULE_LICENSE("GPL");
2409 MODULE_DESCRIPTION("The NFSv4 flexfile layout driver");
2410
2411 module_init(nfs4flexfilelayout_init);
2412 module_exit(nfs4flexfilelayout_exit);