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         pnfs_generic_pg_check_layout(pgio);
 850         /* Use full layout for now */
 851         if (!pgio->pg_lseg)
 852                 ff_layout_pg_get_read(pgio, req, false);
 853         else if (ff_layout_avoid_read_on_rw(pgio->pg_lseg))
 854                 ff_layout_pg_get_read(pgio, req, true);
 855
 856         /* If no lseg, fall back to read through mds */
 857         if (pgio->pg_lseg == NULL)
 858                 goto out_mds;
 859
 860         ds = ff_layout_choose_best_ds_for_read(pgio->pg_lseg, 0, &ds_idx);
 861         if (!ds) {
 862                 if (!ff_layout_no_fallback_to_mds(pgio->pg_lseg))
 863                         goto out_mds;
 864                 pnfs_put_lseg(pgio->pg_lseg);
 865                 pgio->pg_lseg = NULL;
 866                 /* Sleep for 1 second before retrying */
 867                 ssleep(1);
 868                 goto retry;
 869         }
 870
 871         mirror = FF_LAYOUT_COMP(pgio->pg_lseg, ds_idx);
 872
 873         pgio->pg_mirror_idx = ds_idx;
 874
 875         /* read always uses only one mirror - idx 0 for pgio layer */
 876         pgm = &pgio->pg_mirrors[0];
 877         pgm->pg_bsize = mirror->mirror_ds->ds_versions[0].rsize;
 878
 879         return;
 880 out_mds:
 881         pnfs_put_lseg(pgio->pg_lseg);
 882         pgio->pg_lseg = NULL;
 883         nfs_pageio_reset_read_mds(pgio);
 884 }
 885
 886 static void
 887 ff_layout_pg_init_write(struct nfs_pageio_descriptor *pgio,
 888                         struct nfs_page *req)
 889 {
 890         struct nfs4_ff_layout_mirror *mirror;
 891         struct nfs_pgio_mirror *pgm;
 892         struct nfs_commit_info cinfo;
 893         struct nfs4_pnfs_ds *ds;
 894         int i;
 895         int status;
 896
 897 retry:
 898         pnfs_generic_pg_check_layout(pgio);
 899         if (!pgio->pg_lseg) {
 900                 pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
 901                                                    req->wb_context,
 902                                                    0,
 903                                                    NFS4_MAX_UINT64,
 904                                                    IOMODE_RW,
 905                                                    false,
 906                                                    GFP_NOFS);
 907                 if (IS_ERR(pgio->pg_lseg)) {
 908                         pgio->pg_error = PTR_ERR(pgio->pg_lseg);
 909                         pgio->pg_lseg = NULL;
 910                         return;
 911                 }
 912         }
 913         /* If no lseg, fall back to write through mds */
 914         if (pgio->pg_lseg == NULL)
 915                 goto out_mds;
 916
 917         nfs_init_cinfo(&cinfo, pgio->pg_inode, pgio->pg_dreq);
 918         status = ff_layout_alloc_commit_info(pgio->pg_lseg, &cinfo, GFP_NOFS);
 919         if (status < 0)
 920                 goto out_mds;
 921
 922         /* Use a direct mapping of ds_idx to pgio mirror_idx */
 923         if (WARN_ON_ONCE(pgio->pg_mirror_count !=
 924             FF_LAYOUT_MIRROR_COUNT(pgio->pg_lseg)))
 925                 goto out_mds;
 926
 927         for (i = 0; i < pgio->pg_mirror_count; i++) {
 928                 ds = nfs4_ff_layout_prepare_ds(pgio->pg_lseg, i, true);
 929                 if (!ds) {
 930                         if (!ff_layout_no_fallback_to_mds(pgio->pg_lseg))
 931                                 goto out_mds;
 932                         pnfs_put_lseg(pgio->pg_lseg);
 933                         pgio->pg_lseg = NULL;
 934                         /* Sleep for 1 second before retrying */
 935                         ssleep(1);
 936                         goto retry;
 937                 }
 938                 pgm = &pgio->pg_mirrors[i];
 939                 mirror = FF_LAYOUT_COMP(pgio->pg_lseg, i);
 940                 pgm->pg_bsize = mirror->mirror_ds->ds_versions[0].wsize;
 941         }
 942
 943         return;
 944
 945 out_mds:
 946         pnfs_put_lseg(pgio->pg_lseg);
 947         pgio->pg_lseg = NULL;
 948         nfs_pageio_reset_write_mds(pgio);
 949 }
 950
 951 static unsigned int
 952 ff_layout_pg_get_mirror_count_write(struct nfs_pageio_descriptor *pgio,
 953                                     struct nfs_page *req)
 954 {
 955         if (!pgio->pg_lseg) {
 956                 pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
 957                                                    req->wb_context,
 958                                                    0,
 959                                                    NFS4_MAX_UINT64,
 960                                                    IOMODE_RW,
 961                                                    false,
 962                                                    GFP_NOFS);
 963                 if (IS_ERR(pgio->pg_lseg)) {
 964                         pgio->pg_error = PTR_ERR(pgio->pg_lseg);
 965                         pgio->pg_lseg = NULL;
 966                         goto out;
 967                 }
 968         }
 969         if (pgio->pg_lseg)
 970                 return FF_LAYOUT_MIRROR_COUNT(pgio->pg_lseg);
 971
 972         /* no lseg means that pnfs is not in use, so no mirroring here */
 973         nfs_pageio_reset_write_mds(pgio);
 974 out:
 975         return 1;
 976 }
 977
 978 static const struct nfs_pageio_ops ff_layout_pg_read_ops = {
 979         .pg_init = ff_layout_pg_init_read,
 980         .pg_test = pnfs_generic_pg_test,
 981         .pg_doio = pnfs_generic_pg_readpages,
 982         .pg_cleanup = pnfs_generic_pg_cleanup,
 983 };
 984
 985 static const struct nfs_pageio_ops ff_layout_pg_write_ops = {
 986         .pg_init = ff_layout_pg_init_write,
 987         .pg_test = pnfs_generic_pg_test,
 988         .pg_doio = pnfs_generic_pg_writepages,
 989         .pg_get_mirror_count = ff_layout_pg_get_mirror_count_write,
 990         .pg_cleanup = pnfs_generic_pg_cleanup,
 991 };
 992
 993 static void ff_layout_reset_write(struct nfs_pgio_header *hdr, bool retry_pnfs)
 994 {
 995         struct rpc_task *task = &hdr->task;
 996
 997         pnfs_layoutcommit_inode(hdr->inode, false);
 998
 999         if (retry_pnfs) {
1000                 dprintk("%s Reset task %5u for i/o through pNFS "
1001                         "(req %s/%llu, %u bytes @ offset %llu)\n", __func__,
1002                         hdr->task.tk_pid,
1003                         hdr->inode->i_sb->s_id,
1004                         (unsigned long long)NFS_FILEID(hdr->inode),
1005                         hdr->args.count,
1006                         (unsigned long long)hdr->args.offset);
1007
1008                 hdr->completion_ops->reschedule_io(hdr);
1009                 return;
1010         }
1011
1012         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
1013                 dprintk("%s Reset task %5u for i/o through MDS "
1014                         "(req %s/%llu, %u bytes @ offset %llu)\n", __func__,
1015                         hdr->task.tk_pid,
1016                         hdr->inode->i_sb->s_id,
1017                         (unsigned long long)NFS_FILEID(hdr->inode),
1018                         hdr->args.count,
1019                         (unsigned long long)hdr->args.offset);
1020
1021                 task->tk_status = pnfs_write_done_resend_to_mds(hdr);
1022         }
1023 }
1024
1025 static void ff_layout_reset_read(struct nfs_pgio_header *hdr)
1026 {
1027         struct rpc_task *task = &hdr->task;
1028
1029         pnfs_layoutcommit_inode(hdr->inode, false);
1030
1031         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
1032                 dprintk("%s Reset task %5u for i/o through MDS "
1033                         "(req %s/%llu, %u bytes @ offset %llu)\n", __func__,
1034                         hdr->task.tk_pid,
1035                         hdr->inode->i_sb->s_id,
1036                         (unsigned long long)NFS_FILEID(hdr->inode),
1037                         hdr->args.count,
1038                         (unsigned long long)hdr->args.offset);
1039
1040                 task->tk_status = pnfs_read_done_resend_to_mds(hdr);
1041         }
1042 }
1043
1044 static int ff_layout_async_handle_error_v4(struct rpc_task *task,
1045                                            struct nfs4_state *state,
1046                                            struct nfs_client *clp,
1047                                            struct pnfs_layout_segment *lseg,
1048                                            int idx)
1049 {
1050         struct pnfs_layout_hdr *lo = lseg->pls_layout;
1051         struct inode *inode = lo->plh_inode;
1052         struct nfs_server *mds_server = NFS_SERVER(inode);
1053
1054         struct nfs4_deviceid_node *devid = FF_LAYOUT_DEVID_NODE(lseg, idx);
1055         struct nfs_client *mds_client = mds_server->nfs_client;
1056         struct nfs4_slot_table *tbl = &clp->cl_session->fc_slot_table;
1057
1058         switch (task->tk_status) {
1059         /* MDS state errors */
1060         case -NFS4ERR_DELEG_REVOKED:
1061         case -NFS4ERR_ADMIN_REVOKED:
1062         case -NFS4ERR_BAD_STATEID:
1063                 if (state == NULL)
1064                         break;
1065                 nfs_remove_bad_delegation(state->inode, NULL);
1066         case -NFS4ERR_OPENMODE:
1067                 if (state == NULL)
1068                         break;
1069                 if (nfs4_schedule_stateid_recovery(mds_server, state) < 0)
1070                         goto out_bad_stateid;
1071                 goto wait_on_recovery;
1072         case -NFS4ERR_EXPIRED:
1073                 if (state != NULL) {
1074                         if (nfs4_schedule_stateid_recovery(mds_server, state) < 0)
1075                                 goto out_bad_stateid;
1076                 }
1077                 nfs4_schedule_lease_recovery(mds_client);
1078                 goto wait_on_recovery;
1079         /* DS session errors */
1080         case -NFS4ERR_BADSESSION:
1081         case -NFS4ERR_BADSLOT:
1082         case -NFS4ERR_BAD_HIGH_SLOT:
1083         case -NFS4ERR_DEADSESSION:
1084         case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1085         case -NFS4ERR_SEQ_FALSE_RETRY:
1086         case -NFS4ERR_SEQ_MISORDERED:
1087                 dprintk("%s ERROR %d, Reset session. Exchangeid "
1088                         "flags 0x%x\n", __func__, task->tk_status,
1089                         clp->cl_exchange_flags);
1090                 nfs4_schedule_session_recovery(clp->cl_session, task->tk_status);
1091                 break;
1092         case -NFS4ERR_DELAY:
1093         case -NFS4ERR_GRACE:
1094                 rpc_delay(task, FF_LAYOUT_POLL_RETRY_MAX);
1095                 break;
1096         case -NFS4ERR_RETRY_UNCACHED_REP:
1097                 break;
1098         /* Invalidate Layout errors */
1099         case -NFS4ERR_PNFS_NO_LAYOUT:
1100         case -ESTALE:           /* mapped NFS4ERR_STALE */
1101         case -EBADHANDLE:       /* mapped NFS4ERR_BADHANDLE */
1102         case -EISDIR:           /* mapped NFS4ERR_ISDIR */
1103         case -NFS4ERR_FHEXPIRED:
1104         case -NFS4ERR_WRONG_TYPE:
1105                 dprintk("%s Invalid layout error %d\n", __func__,
1106                         task->tk_status);
1107                 /*
1108                  * Destroy layout so new i/o will get a new layout.
1109                  * Layout will not be destroyed until all current lseg
1110                  * references are put. Mark layout as invalid to resend failed
1111                  * i/o and all i/o waiting on the slot table to the MDS until
1112                  * layout is destroyed and a new valid layout is obtained.
1113                  */
1114                 pnfs_destroy_layout(NFS_I(inode));
1115                 rpc_wake_up(&tbl->slot_tbl_waitq);
1116                 goto reset;
1117         /* RPC connection errors */
1118         case -ECONNREFUSED:
1119         case -EHOSTDOWN:
1120         case -EHOSTUNREACH:
1121         case -ENETUNREACH:
1122         case -EIO:
1123         case -ETIMEDOUT:
1124         case -EPIPE:
1125                 dprintk("%s DS connection error %d\n", __func__,
1126                         task->tk_status);
1127                 nfs4_delete_deviceid(devid->ld, devid->nfs_client,
1128                                 &devid->deviceid);
1129                 rpc_wake_up(&tbl->slot_tbl_waitq);
1130                 /* fall through */
1131         default:
1132                 if (ff_layout_avoid_mds_available_ds(lseg))
1133                         return -NFS4ERR_RESET_TO_PNFS;
1134 reset:
1135                 dprintk("%s Retry through MDS. Error %d\n", __func__,
1136                         task->tk_status);
1137                 return -NFS4ERR_RESET_TO_MDS;
1138         }
1139 out:
1140         task->tk_status = 0;
1141         return -EAGAIN;
1142 out_bad_stateid:
1143         task->tk_status = -EIO;
1144         return 0;
1145 wait_on_recovery:
1146         rpc_sleep_on(&mds_client->cl_rpcwaitq, task, NULL);
1147         if (test_bit(NFS4CLNT_MANAGER_RUNNING, &mds_client->cl_state) == 0)
1148                 rpc_wake_up_queued_task(&mds_client->cl_rpcwaitq, task);
1149         goto out;
1150 }
1151
1152 /* Retry all errors through either pNFS or MDS except for -EJUKEBOX */
1153 static int ff_layout_async_handle_error_v3(struct rpc_task *task,
1154                                            struct pnfs_layout_segment *lseg,
1155                                            int idx)
1156 {
1157         struct nfs4_deviceid_node *devid = FF_LAYOUT_DEVID_NODE(lseg, idx);
1158
1159         switch (task->tk_status) {
1160         /* File access problems. Don't mark the device as unavailable */
1161         case -EACCES:
1162         case -ESTALE:
1163         case -EISDIR:
1164         case -EBADHANDLE:
1165         case -ELOOP:
1166         case -ENOSPC:
1167                 break;
1168         case -EJUKEBOX:
1169                 nfs_inc_stats(lseg->pls_layout->plh_inode, NFSIOS_DELAY);
1170                 goto out_retry;
1171         default:
1172                 dprintk("%s DS connection error %d\n", __func__,
1173                         task->tk_status);
1174                 nfs4_delete_deviceid(devid->ld, devid->nfs_client,
1175                                 &devid->deviceid);
1176         }
1177         /* FIXME: Need to prevent infinite looping here. */
1178         return -NFS4ERR_RESET_TO_PNFS;
1179 out_retry:
1180         task->tk_status = 0;
1181         rpc_restart_call_prepare(task);
1182         rpc_delay(task, NFS_JUKEBOX_RETRY_TIME);
1183         return -EAGAIN;
1184 }
1185
1186 static int ff_layout_async_handle_error(struct rpc_task *task,
1187                                         struct nfs4_state *state,
1188                                         struct nfs_client *clp,
1189                                         struct pnfs_layout_segment *lseg,
1190                                         int idx)
1191 {
1192         int vers = clp->cl_nfs_mod->rpc_vers->number;
1193
1194         if (task->tk_status >= 0)
1195                 return 0;
1196
1197         /* Handle the case of an invalid layout segment */
1198         if (!pnfs_is_valid_lseg(lseg))
1199                 return -NFS4ERR_RESET_TO_PNFS;
1200
1201         switch (vers) {
1202         case 3:
1203                 return ff_layout_async_handle_error_v3(task, lseg, idx);
1204         case 4:
1205                 return ff_layout_async_handle_error_v4(task, state, clp,
1206                                                        lseg, idx);
1207         default:
1208                 /* should never happen */
1209                 WARN_ON_ONCE(1);
1210                 return 0;
1211         }
1212 }
1213
1214 static void ff_layout_io_track_ds_error(struct pnfs_layout_segment *lseg,
1215                                         int idx, u64 offset, u64 length,
1216                                         u32 status, int opnum, int error)
1217 {
1218         struct nfs4_ff_layout_mirror *mirror;
1219         int err;
1220
1221         if (status == 0) {
1222                 switch (error) {
1223                 case -ETIMEDOUT:
1224                 case -EPFNOSUPPORT:
1225                 case -EPROTONOSUPPORT:
1226                 case -EOPNOTSUPP:
1227                 case -ECONNREFUSED:
1228                 case -ECONNRESET:
1229                 case -EHOSTDOWN:
1230                 case -EHOSTUNREACH:
1231                 case -ENETUNREACH:
1232                 case -EADDRINUSE:
1233                 case -ENOBUFS:
1234                 case -EPIPE:
1235                 case -EPERM:
1236                         status = NFS4ERR_NXIO;
1237                         break;
1238                 case -EACCES:
1239                         status = NFS4ERR_ACCESS;
1240                         break;
1241                 default:
1242                         return;
1243                 }
1244         }
1245
1246         switch (status) {
1247         case NFS4ERR_DELAY:
1248         case NFS4ERR_GRACE:
1249                 return;
1250         default:
1251                 break;
1252         }
1253
1254         mirror = FF_LAYOUT_COMP(lseg, idx);
1255         err = ff_layout_track_ds_error(FF_LAYOUT_FROM_HDR(lseg->pls_layout),
1256                                        mirror, offset, length, status, opnum,
1257                                        GFP_NOIO);
1258         pnfs_error_mark_layout_for_return(lseg->pls_layout->plh_inode, lseg);
1259         dprintk("%s: err %d op %d status %u\n", __func__, err, opnum, status);
1260 }
1261
1262 /* NFS_PROTO call done callback routines */
1263 static int ff_layout_read_done_cb(struct rpc_task *task,
1264                                 struct nfs_pgio_header *hdr)
1265 {
1266         int err;
1267
1268         trace_nfs4_pnfs_read(hdr, task->tk_status);
1269         if (task->tk_status < 0)
1270                 ff_layout_io_track_ds_error(hdr->lseg, hdr->pgio_mirror_idx,
1271                                             hdr->args.offset, hdr->args.count,
1272                                             hdr->res.op_status, OP_READ,
1273                                             task->tk_status);
1274         err = ff_layout_async_handle_error(task, hdr->args.context->state,
1275                                            hdr->ds_clp, hdr->lseg,
1276                                            hdr->pgio_mirror_idx);
1277
1278         switch (err) {
1279         case -NFS4ERR_RESET_TO_PNFS:
1280                 if (ff_layout_choose_best_ds_for_read(hdr->lseg,
1281                                         hdr->pgio_mirror_idx + 1,
1282                                         &hdr->pgio_mirror_idx))
1283                         goto out_eagain;
1284                 ff_layout_read_record_layoutstats_done(task, hdr);
1285                 pnfs_read_resend_pnfs(hdr);
1286                 return task->tk_status;
1287         case -NFS4ERR_RESET_TO_MDS:
1288                 ff_layout_reset_read(hdr);
1289                 return task->tk_status;
1290         case -EAGAIN:
1291                 goto out_eagain;
1292         }
1293
1294         return 0;
1295 out_eagain:
1296         rpc_restart_call_prepare(task);
1297         return -EAGAIN;
1298 }
1299
1300 static bool
1301 ff_layout_need_layoutcommit(struct pnfs_layout_segment *lseg)
1302 {
1303         return !(FF_LAYOUT_LSEG(lseg)->flags & FF_FLAGS_NO_LAYOUTCOMMIT);
1304 }
1305
1306 /*
1307  * We reference the rpc_cred of the first WRITE that triggers the need for
1308  * a LAYOUTCOMMIT, and use it to send the layoutcommit compound.
1309  * rfc5661 is not clear about which credential should be used.
1310  *
1311  * Flexlayout client should treat DS replied FILE_SYNC as DATA_SYNC, so
1312  * to follow http://www.rfc-editor.org/errata_search.php?rfc=5661&eid=2751
1313  * we always send layoutcommit after DS writes.
1314  */
1315 static void
1316 ff_layout_set_layoutcommit(struct inode *inode,
1317                 struct pnfs_layout_segment *lseg,
1318                 loff_t end_offset)
1319 {
1320         if (!ff_layout_need_layoutcommit(lseg))
1321                 return;
1322
1323         pnfs_set_layoutcommit(inode, lseg, end_offset);
1324         dprintk("%s inode %lu pls_end_pos %llu\n", __func__, inode->i_ino,
1325                 (unsigned long long) NFS_I(inode)->layout->plh_lwb);
1326 }
1327
1328 static bool
1329 ff_layout_device_unavailable(struct pnfs_layout_segment *lseg, int idx)
1330 {
1331         /* No mirroring for now */
1332         struct nfs4_deviceid_node *node = FF_LAYOUT_DEVID_NODE(lseg, idx);
1333
1334         return ff_layout_test_devid_unavailable(node);
1335 }
1336
1337 static void ff_layout_read_record_layoutstats_start(struct rpc_task *task,
1338                 struct nfs_pgio_header *hdr)
1339 {
1340         if (test_and_set_bit(NFS_IOHDR_STAT, &hdr->flags))
1341                 return;
1342         nfs4_ff_layout_stat_io_start_read(hdr->inode,
1343                         FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
1344                         hdr->args.count,
1345                         task->tk_start);
1346 }
1347
1348 static void ff_layout_read_record_layoutstats_done(struct rpc_task *task,
1349                 struct nfs_pgio_header *hdr)
1350 {
1351         if (!test_and_clear_bit(NFS_IOHDR_STAT, &hdr->flags))
1352                 return;
1353         nfs4_ff_layout_stat_io_end_read(task,
1354                         FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
1355                         hdr->args.count,
1356                         hdr->res.count);
1357 }
1358
1359 static int ff_layout_read_prepare_common(struct rpc_task *task,
1360                                          struct nfs_pgio_header *hdr)
1361 {
1362         if (unlikely(test_bit(NFS_CONTEXT_BAD, &hdr->args.context->flags))) {
1363                 rpc_exit(task, -EIO);
1364                 return -EIO;
1365         }
1366         if (ff_layout_device_unavailable(hdr->lseg, hdr->pgio_mirror_idx)) {
1367                 rpc_exit(task, -EHOSTDOWN);
1368                 return -EAGAIN;
1369         }
1370
1371         ff_layout_read_record_layoutstats_start(task, hdr);
1372         return 0;
1373 }
1374
1375 /*
1376  * Call ops for the async read/write cases
1377  * In the case of dense layouts, the offset needs to be reset to its
1378  * original value.
1379  */
1380 static void ff_layout_read_prepare_v3(struct rpc_task *task, void *data)
1381 {
1382         struct nfs_pgio_header *hdr = data;
1383
1384         if (ff_layout_read_prepare_common(task, hdr))
1385                 return;
1386
1387         rpc_call_start(task);
1388 }
1389
1390 static void ff_layout_read_prepare_v4(struct rpc_task *task, void *data)
1391 {
1392         struct nfs_pgio_header *hdr = data;
1393
1394         if (nfs4_setup_sequence(hdr->ds_clp,
1395                                 &hdr->args.seq_args,
1396                                 &hdr->res.seq_res,
1397                                 task))
1398                 return;
1399
1400         if (ff_layout_read_prepare_common(task, hdr))
1401                 return;
1402
1403         if (nfs4_set_rw_stateid(&hdr->args.stateid, hdr->args.context,
1404                         hdr->args.lock_context, FMODE_READ) == -EIO)
1405                 rpc_exit(task, -EIO); /* lost lock, terminate I/O */
1406 }
1407
1408 static void ff_layout_read_call_done(struct rpc_task *task, void *data)
1409 {
1410         struct nfs_pgio_header *hdr = data;
1411
1412         dprintk("--> %s task->tk_status %d\n", __func__, task->tk_status);
1413
1414         if (test_bit(NFS_IOHDR_REDO, &hdr->flags) &&
1415             task->tk_status == 0) {
1416                 nfs4_sequence_done(task, &hdr->res.seq_res);
1417                 return;
1418         }
1419
1420         /* Note this may cause RPC to be resent */
1421         hdr->mds_ops->rpc_call_done(task, hdr);
1422 }
1423
1424 static void ff_layout_read_count_stats(struct rpc_task *task, void *data)
1425 {
1426         struct nfs_pgio_header *hdr = data;
1427
1428         ff_layout_read_record_layoutstats_done(task, hdr);
1429         rpc_count_iostats_metrics(task,
1430             &NFS_CLIENT(hdr->inode)->cl_metrics[NFSPROC4_CLNT_READ]);
1431 }
1432
1433 static void ff_layout_read_release(void *data)
1434 {
1435         struct nfs_pgio_header *hdr = data;
1436
1437         ff_layout_read_record_layoutstats_done(&hdr->task, hdr);
1438         pnfs_generic_rw_release(data);
1439 }
1440
1441
1442 static int ff_layout_write_done_cb(struct rpc_task *task,
1443                                 struct nfs_pgio_header *hdr)
1444 {
1445         loff_t end_offs = 0;
1446         int err;
1447
1448         trace_nfs4_pnfs_write(hdr, task->tk_status);
1449         if (task->tk_status < 0)
1450                 ff_layout_io_track_ds_error(hdr->lseg, hdr->pgio_mirror_idx,
1451                                             hdr->args.offset, hdr->args.count,
1452                                             hdr->res.op_status, OP_WRITE,
1453                                             task->tk_status);
1454         err = ff_layout_async_handle_error(task, hdr->args.context->state,
1455                                            hdr->ds_clp, hdr->lseg,
1456                                            hdr->pgio_mirror_idx);
1457
1458         switch (err) {
1459         case -NFS4ERR_RESET_TO_PNFS:
1460                 ff_layout_reset_write(hdr, true);
1461                 return task->tk_status;
1462         case -NFS4ERR_RESET_TO_MDS:
1463                 ff_layout_reset_write(hdr, false);
1464                 return task->tk_status;
1465         case -EAGAIN:
1466                 return -EAGAIN;
1467         }
1468
1469         if (hdr->res.verf->committed == NFS_FILE_SYNC ||
1470             hdr->res.verf->committed == NFS_DATA_SYNC)
1471                 end_offs = hdr->mds_offset + (loff_t)hdr->res.count;
1472
1473         /* Note: if the write is unstable, don't set end_offs until commit */
1474         ff_layout_set_layoutcommit(hdr->inode, hdr->lseg, end_offs);
1475
1476         /* zero out fattr since we don't care DS attr at all */
1477         hdr->fattr.valid = 0;
1478         if (task->tk_status >= 0)
1479                 nfs_writeback_update_inode(hdr);
1480
1481         return 0;
1482 }
1483
1484 static int ff_layout_commit_done_cb(struct rpc_task *task,
1485                                      struct nfs_commit_data *data)
1486 {
1487         int err;
1488
1489         trace_nfs4_pnfs_commit_ds(data, task->tk_status);
1490         if (task->tk_status < 0)
1491                 ff_layout_io_track_ds_error(data->lseg, data->ds_commit_index,
1492                                             data->args.offset, data->args.count,
1493                                             data->res.op_status, OP_COMMIT,
1494                                             task->tk_status);
1495         err = ff_layout_async_handle_error(task, NULL, data->ds_clp,
1496                                            data->lseg, data->ds_commit_index);
1497
1498         switch (err) {
1499         case -NFS4ERR_RESET_TO_PNFS:
1500                 pnfs_generic_prepare_to_resend_writes(data);
1501                 return -EAGAIN;
1502         case -NFS4ERR_RESET_TO_MDS:
1503                 pnfs_generic_prepare_to_resend_writes(data);
1504                 return -EAGAIN;
1505         case -EAGAIN:
1506                 rpc_restart_call_prepare(task);
1507                 return -EAGAIN;
1508         }
1509
1510         ff_layout_set_layoutcommit(data->inode, data->lseg, data->lwb);
1511
1512         return 0;
1513 }
1514
1515 static void ff_layout_write_record_layoutstats_start(struct rpc_task *task,
1516                 struct nfs_pgio_header *hdr)
1517 {
1518         if (test_and_set_bit(NFS_IOHDR_STAT, &hdr->flags))
1519                 return;
1520         nfs4_ff_layout_stat_io_start_write(hdr->inode,
1521                         FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
1522                         hdr->args.count,
1523                         task->tk_start);
1524 }
1525
1526 static void ff_layout_write_record_layoutstats_done(struct rpc_task *task,
1527                 struct nfs_pgio_header *hdr)
1528 {
1529         if (!test_and_clear_bit(NFS_IOHDR_STAT, &hdr->flags))
1530                 return;
1531         nfs4_ff_layout_stat_io_end_write(task,
1532                         FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
1533                         hdr->args.count, hdr->res.count,
1534                         hdr->res.verf->committed);
1535 }
1536
1537 static int ff_layout_write_prepare_common(struct rpc_task *task,
1538                                           struct nfs_pgio_header *hdr)
1539 {
1540         if (unlikely(test_bit(NFS_CONTEXT_BAD, &hdr->args.context->flags))) {
1541                 rpc_exit(task, -EIO);
1542                 return -EIO;
1543         }
1544
1545         if (ff_layout_device_unavailable(hdr->lseg, hdr->pgio_mirror_idx)) {
1546                 rpc_exit(task, -EHOSTDOWN);
1547                 return -EAGAIN;
1548         }
1549
1550         ff_layout_write_record_layoutstats_start(task, hdr);
1551         return 0;
1552 }
1553
1554 static void ff_layout_write_prepare_v3(struct rpc_task *task, void *data)
1555 {
1556         struct nfs_pgio_header *hdr = data;
1557
1558         if (ff_layout_write_prepare_common(task, hdr))
1559                 return;
1560
1561         rpc_call_start(task);
1562 }
1563
1564 static void ff_layout_write_prepare_v4(struct rpc_task *task, void *data)
1565 {
1566         struct nfs_pgio_header *hdr = data;
1567
1568         if (nfs4_setup_sequence(hdr->ds_clp,
1569                                 &hdr->args.seq_args,
1570                                 &hdr->res.seq_res,
1571                                 task))
1572                 return;
1573
1574         if (ff_layout_write_prepare_common(task, hdr))
1575                 return;
1576
1577         if (nfs4_set_rw_stateid(&hdr->args.stateid, hdr->args.context,
1578                         hdr->args.lock_context, FMODE_WRITE) == -EIO)
1579                 rpc_exit(task, -EIO); /* lost lock, terminate I/O */
1580 }
1581
1582 static void ff_layout_write_call_done(struct rpc_task *task, void *data)
1583 {
1584         struct nfs_pgio_header *hdr = data;
1585
1586         if (test_bit(NFS_IOHDR_REDO, &hdr->flags) &&
1587             task->tk_status == 0) {
1588                 nfs4_sequence_done(task, &hdr->res.seq_res);
1589                 return;
1590         }
1591
1592         /* Note this may cause RPC to be resent */
1593         hdr->mds_ops->rpc_call_done(task, hdr);
1594 }
1595
1596 static void ff_layout_write_count_stats(struct rpc_task *task, void *data)
1597 {
1598         struct nfs_pgio_header *hdr = data;
1599
1600         ff_layout_write_record_layoutstats_done(task, hdr);
1601         rpc_count_iostats_metrics(task,
1602             &NFS_CLIENT(hdr->inode)->cl_metrics[NFSPROC4_CLNT_WRITE]);
1603 }
1604
1605 static void ff_layout_write_release(void *data)
1606 {
1607         struct nfs_pgio_header *hdr = data;
1608
1609         ff_layout_write_record_layoutstats_done(&hdr->task, hdr);
1610         pnfs_generic_rw_release(data);
1611 }
1612
1613 static void ff_layout_commit_record_layoutstats_start(struct rpc_task *task,
1614                 struct nfs_commit_data *cdata)
1615 {
1616         if (test_and_set_bit(NFS_IOHDR_STAT, &cdata->flags))
1617                 return;
1618         nfs4_ff_layout_stat_io_start_write(cdata->inode,
1619                         FF_LAYOUT_COMP(cdata->lseg, cdata->ds_commit_index),
1620                         0, task->tk_start);
1621 }
1622
1623 static void ff_layout_commit_record_layoutstats_done(struct rpc_task *task,
1624                 struct nfs_commit_data *cdata)
1625 {
1626         struct nfs_page *req;
1627         __u64 count = 0;
1628
1629         if (!test_and_clear_bit(NFS_IOHDR_STAT, &cdata->flags))
1630                 return;
1631
1632         if (task->tk_status == 0) {
1633                 list_for_each_entry(req, &cdata->pages, wb_list)
1634                         count += req->wb_bytes;
1635         }
1636         nfs4_ff_layout_stat_io_end_write(task,
1637                         FF_LAYOUT_COMP(cdata->lseg, cdata->ds_commit_index),
1638                         count, count, NFS_FILE_SYNC);
1639 }
1640
1641 static void ff_layout_commit_prepare_common(struct rpc_task *task,
1642                 struct nfs_commit_data *cdata)
1643 {
1644         ff_layout_commit_record_layoutstats_start(task, cdata);
1645 }
1646
1647 static void ff_layout_commit_prepare_v3(struct rpc_task *task, void *data)
1648 {
1649         ff_layout_commit_prepare_common(task, data);
1650         rpc_call_start(task);
1651 }
1652
1653 static void ff_layout_commit_prepare_v4(struct rpc_task *task, void *data)
1654 {
1655         struct nfs_commit_data *wdata = data;
1656
1657         if (nfs4_setup_sequence(wdata->ds_clp,
1658                                 &wdata->args.seq_args,
1659                                 &wdata->res.seq_res,
1660                                 task))
1661                 return;
1662         ff_layout_commit_prepare_common(task, data);
1663 }
1664
1665 static void ff_layout_commit_done(struct rpc_task *task, void *data)
1666 {
1667         pnfs_generic_write_commit_done(task, data);
1668 }
1669
1670 static void ff_layout_commit_count_stats(struct rpc_task *task, void *data)
1671 {
1672         struct nfs_commit_data *cdata = data;
1673
1674         ff_layout_commit_record_layoutstats_done(task, cdata);
1675         rpc_count_iostats_metrics(task,
1676             &NFS_CLIENT(cdata->inode)->cl_metrics[NFSPROC4_CLNT_COMMIT]);
1677 }
1678
1679 static void ff_layout_commit_release(void *data)
1680 {
1681         struct nfs_commit_data *cdata = data;
1682
1683         ff_layout_commit_record_layoutstats_done(&cdata->task, cdata);
1684         pnfs_generic_commit_release(data);
1685 }
1686
1687 static const struct rpc_call_ops ff_layout_read_call_ops_v3 = {
1688         .rpc_call_prepare = ff_layout_read_prepare_v3,
1689         .rpc_call_done = ff_layout_read_call_done,
1690         .rpc_count_stats = ff_layout_read_count_stats,
1691         .rpc_release = ff_layout_read_release,
1692 };
1693
1694 static const struct rpc_call_ops ff_layout_read_call_ops_v4 = {
1695         .rpc_call_prepare = ff_layout_read_prepare_v4,
1696         .rpc_call_done = ff_layout_read_call_done,
1697         .rpc_count_stats = ff_layout_read_count_stats,
1698         .rpc_release = ff_layout_read_release,
1699 };
1700
1701 static const struct rpc_call_ops ff_layout_write_call_ops_v3 = {
1702         .rpc_call_prepare = ff_layout_write_prepare_v3,
1703         .rpc_call_done = ff_layout_write_call_done,
1704         .rpc_count_stats = ff_layout_write_count_stats,
1705         .rpc_release = ff_layout_write_release,
1706 };
1707
1708 static const struct rpc_call_ops ff_layout_write_call_ops_v4 = {
1709         .rpc_call_prepare = ff_layout_write_prepare_v4,
1710         .rpc_call_done = ff_layout_write_call_done,
1711         .rpc_count_stats = ff_layout_write_count_stats,
1712         .rpc_release = ff_layout_write_release,
1713 };
1714
1715 static const struct rpc_call_ops ff_layout_commit_call_ops_v3 = {
1716         .rpc_call_prepare = ff_layout_commit_prepare_v3,
1717         .rpc_call_done = ff_layout_commit_done,
1718         .rpc_count_stats = ff_layout_commit_count_stats,
1719         .rpc_release = ff_layout_commit_release,
1720 };
1721
1722 static const struct rpc_call_ops ff_layout_commit_call_ops_v4 = {
1723         .rpc_call_prepare = ff_layout_commit_prepare_v4,
1724         .rpc_call_done = ff_layout_commit_done,
1725         .rpc_count_stats = ff_layout_commit_count_stats,
1726         .rpc_release = ff_layout_commit_release,
1727 };
1728
1729 static enum pnfs_try_status
1730 ff_layout_read_pagelist(struct nfs_pgio_header *hdr)
1731 {
1732         struct pnfs_layout_segment *lseg = hdr->lseg;
1733         struct nfs4_pnfs_ds *ds;
1734         struct rpc_clnt *ds_clnt;
1735         struct rpc_cred *ds_cred;
1736         loff_t offset = hdr->args.offset;
1737         u32 idx = hdr->pgio_mirror_idx;
1738         int vers;
1739         struct nfs_fh *fh;
1740
1741         dprintk("--> %s ino %lu pgbase %u req %zu@%llu\n",
1742                 __func__, hdr->inode->i_ino,
1743                 hdr->args.pgbase, (size_t)hdr->args.count, offset);
1744
1745         ds = nfs4_ff_layout_prepare_ds(lseg, idx, false);
1746         if (!ds)
1747                 goto out_failed;
1748
1749         ds_clnt = nfs4_ff_find_or_create_ds_client(lseg, idx, ds->ds_clp,
1750                                                    hdr->inode);
1751         if (IS_ERR(ds_clnt))
1752                 goto out_failed;
1753
1754         ds_cred = ff_layout_get_ds_cred(lseg, idx, hdr->cred);
1755         if (!ds_cred)
1756                 goto out_failed;
1757
1758         vers = nfs4_ff_layout_ds_version(lseg, idx);
1759
1760         dprintk("%s USE DS: %s cl_count %d vers %d\n", __func__,
1761                 ds->ds_remotestr, atomic_read(&ds->ds_clp->cl_count), vers);
1762
1763         hdr->pgio_done_cb = ff_layout_read_done_cb;
1764         atomic_inc(&ds->ds_clp->cl_count);
1765         hdr->ds_clp = ds->ds_clp;
1766         fh = nfs4_ff_layout_select_ds_fh(lseg, idx);
1767         if (fh)
1768                 hdr->args.fh = fh;
1769         /*
1770          * Note that if we ever decide to split across DSes,
1771          * then we may need to handle dense-like offsets.
1772          */
1773         hdr->args.offset = offset;
1774         hdr->mds_offset = offset;
1775
1776         /* Perform an asynchronous read to ds */
1777         nfs_initiate_pgio(ds_clnt, hdr, ds_cred, ds->ds_clp->rpc_ops,
1778                           vers == 3 ? &ff_layout_read_call_ops_v3 :
1779                                       &ff_layout_read_call_ops_v4,
1780                           0, RPC_TASK_SOFTCONN);
1781         put_rpccred(ds_cred);
1782         return PNFS_ATTEMPTED;
1783
1784 out_failed:
1785         if (ff_layout_avoid_mds_available_ds(lseg))
1786                 return PNFS_TRY_AGAIN;
1787         return PNFS_NOT_ATTEMPTED;
1788 }
1789
1790 /* Perform async writes. */
1791 static enum pnfs_try_status
1792 ff_layout_write_pagelist(struct nfs_pgio_header *hdr, int sync)
1793 {
1794         struct pnfs_layout_segment *lseg = hdr->lseg;
1795         struct nfs4_pnfs_ds *ds;
1796         struct rpc_clnt *ds_clnt;
1797         struct rpc_cred *ds_cred;
1798         loff_t offset = hdr->args.offset;
1799         int vers;
1800         struct nfs_fh *fh;
1801         int idx = hdr->pgio_mirror_idx;
1802
1803         ds = nfs4_ff_layout_prepare_ds(lseg, idx, true);
1804         if (!ds)
1805                 goto out_failed;
1806
1807         ds_clnt = nfs4_ff_find_or_create_ds_client(lseg, idx, ds->ds_clp,
1808                                                    hdr->inode);
1809         if (IS_ERR(ds_clnt))
1810                 goto out_failed;
1811
1812         ds_cred = ff_layout_get_ds_cred(lseg, idx, hdr->cred);
1813         if (!ds_cred)
1814                 goto out_failed;
1815
1816         vers = nfs4_ff_layout_ds_version(lseg, idx);
1817
1818         dprintk("%s ino %lu sync %d req %zu@%llu DS: %s cl_count %d vers %d\n",
1819                 __func__, hdr->inode->i_ino, sync, (size_t) hdr->args.count,
1820                 offset, ds->ds_remotestr, atomic_read(&ds->ds_clp->cl_count),
1821                 vers);
1822
1823         hdr->pgio_done_cb = ff_layout_write_done_cb;
1824         atomic_inc(&ds->ds_clp->cl_count);
1825         hdr->ds_clp = ds->ds_clp;
1826         hdr->ds_commit_idx = idx;
1827         fh = nfs4_ff_layout_select_ds_fh(lseg, idx);
1828         if (fh)
1829                 hdr->args.fh = fh;
1830
1831         /*
1832          * Note that if we ever decide to split across DSes,
1833          * then we may need to handle dense-like offsets.
1834          */
1835         hdr->args.offset = offset;
1836
1837         /* Perform an asynchronous write */
1838         nfs_initiate_pgio(ds_clnt, hdr, ds_cred, ds->ds_clp->rpc_ops,
1839                           vers == 3 ? &ff_layout_write_call_ops_v3 :
1840                                       &ff_layout_write_call_ops_v4,
1841                           sync, RPC_TASK_SOFTCONN);
1842         put_rpccred(ds_cred);
1843         return PNFS_ATTEMPTED;
1844
1845 out_failed:
1846         if (ff_layout_avoid_mds_available_ds(lseg))
1847                 return PNFS_TRY_AGAIN;
1848         return PNFS_NOT_ATTEMPTED;
1849 }
1850
1851 static u32 calc_ds_index_from_commit(struct pnfs_layout_segment *lseg, u32 i)
1852 {
1853         return i;
1854 }
1855
1856 static struct nfs_fh *
1857 select_ds_fh_from_commit(struct pnfs_layout_segment *lseg, u32 i)
1858 {
1859         struct nfs4_ff_layout_segment *flseg = FF_LAYOUT_LSEG(lseg);
1860
1861         /* FIXME: Assume that there is only one NFS version available
1862          * for the DS.
1863          */
1864         return &flseg->mirror_array[i]->fh_versions[0];
1865 }
1866
1867 static int ff_layout_initiate_commit(struct nfs_commit_data *data, int how)
1868 {
1869         struct pnfs_layout_segment *lseg = data->lseg;
1870         struct nfs4_pnfs_ds *ds;
1871         struct rpc_clnt *ds_clnt;
1872         struct rpc_cred *ds_cred;
1873         u32 idx;
1874         int vers, ret;
1875         struct nfs_fh *fh;
1876
1877         idx = calc_ds_index_from_commit(lseg, data->ds_commit_index);
1878         ds = nfs4_ff_layout_prepare_ds(lseg, idx, true);
1879         if (!ds)
1880                 goto out_err;
1881
1882         ds_clnt = nfs4_ff_find_or_create_ds_client(lseg, idx, ds->ds_clp,
1883                                                    data->inode);
1884         if (IS_ERR(ds_clnt))
1885                 goto out_err;
1886
1887         ds_cred = ff_layout_get_ds_cred(lseg, idx, data->cred);
1888         if (!ds_cred)
1889                 goto out_err;
1890
1891         vers = nfs4_ff_layout_ds_version(lseg, idx);
1892
1893         dprintk("%s ino %lu, how %d cl_count %d vers %d\n", __func__,
1894                 data->inode->i_ino, how, atomic_read(&ds->ds_clp->cl_count),
1895                 vers);
1896         data->commit_done_cb = ff_layout_commit_done_cb;
1897         data->cred = ds_cred;
1898         atomic_inc(&ds->ds_clp->cl_count);
1899         data->ds_clp = ds->ds_clp;
1900         fh = select_ds_fh_from_commit(lseg, data->ds_commit_index);
1901         if (fh)
1902                 data->args.fh = fh;
1903
1904         ret = nfs_initiate_commit(ds_clnt, data, ds->ds_clp->rpc_ops,
1905                                    vers == 3 ? &ff_layout_commit_call_ops_v3 :
1906                                                &ff_layout_commit_call_ops_v4,
1907                                    how, RPC_TASK_SOFTCONN);
1908         put_rpccred(ds_cred);
1909         return ret;
1910 out_err:
1911         pnfs_generic_prepare_to_resend_writes(data);
1912         pnfs_generic_commit_release(data);
1913         return -EAGAIN;
1914 }
1915
1916 static int
1917 ff_layout_commit_pagelist(struct inode *inode, struct list_head *mds_pages,
1918                            int how, struct nfs_commit_info *cinfo)
1919 {
1920         return pnfs_generic_commit_pagelist(inode, mds_pages, how, cinfo,
1921                                             ff_layout_initiate_commit);
1922 }
1923
1924 static struct pnfs_ds_commit_info *
1925 ff_layout_get_ds_info(struct inode *inode)
1926 {
1927         struct pnfs_layout_hdr *layout = NFS_I(inode)->layout;
1928
1929         if (layout == NULL)
1930                 return NULL;
1931
1932         return &FF_LAYOUT_FROM_HDR(layout)->commit_info;
1933 }
1934
1935 static void
1936 ff_layout_free_deviceid_node(struct nfs4_deviceid_node *d)
1937 {
1938         nfs4_ff_layout_free_deviceid(container_of(d, struct nfs4_ff_layout_ds,
1939                                                   id_node));
1940 }
1941
1942 static int ff_layout_encode_ioerr(struct xdr_stream *xdr,
1943                                   const struct nfs4_layoutreturn_args *args,
1944                                   const struct nfs4_flexfile_layoutreturn_args *ff_args)
1945 {
1946         __be32 *start;
1947
1948         start = xdr_reserve_space(xdr, 4);
1949         if (unlikely(!start))
1950                 return -E2BIG;
1951
1952         *start = cpu_to_be32(ff_args->num_errors);
1953         /* This assume we always return _ALL_ layouts */
1954         return ff_layout_encode_ds_ioerr(xdr, &ff_args->errors);
1955 }
1956
1957 static void
1958 encode_opaque_fixed(struct xdr_stream *xdr, const void *buf, size_t len)
1959 {
1960         WARN_ON_ONCE(xdr_stream_encode_opaque_fixed(xdr, buf, len) < 0);
1961 }
1962
1963 static void
1964 ff_layout_encode_ff_iostat_head(struct xdr_stream *xdr,
1965                             const nfs4_stateid *stateid,
1966                             const struct nfs42_layoutstat_devinfo *devinfo)
1967 {
1968         __be32 *p;
1969
1970         p = xdr_reserve_space(xdr, 8 + 8);
1971         p = xdr_encode_hyper(p, devinfo->offset);
1972         p = xdr_encode_hyper(p, devinfo->length);
1973         encode_opaque_fixed(xdr, stateid->data, NFS4_STATEID_SIZE);
1974         p = xdr_reserve_space(xdr, 4*8);
1975         p = xdr_encode_hyper(p, devinfo->read_count);
1976         p = xdr_encode_hyper(p, devinfo->read_bytes);
1977         p = xdr_encode_hyper(p, devinfo->write_count);
1978         p = xdr_encode_hyper(p, devinfo->write_bytes);
1979         encode_opaque_fixed(xdr, devinfo->dev_id.data, NFS4_DEVICEID4_SIZE);
1980 }
1981
1982 static void
1983 ff_layout_encode_ff_iostat(struct xdr_stream *xdr,
1984                             const nfs4_stateid *stateid,
1985                             const struct nfs42_layoutstat_devinfo *devinfo)
1986 {
1987         ff_layout_encode_ff_iostat_head(xdr, stateid, devinfo);
1988         ff_layout_encode_ff_layoutupdate(xdr, devinfo,
1989                         devinfo->ld_private.data);
1990 }
1991
1992 /* report nothing for now */
1993 static void ff_layout_encode_iostats_array(struct xdr_stream *xdr,
1994                 const struct nfs4_layoutreturn_args *args,
1995                 struct nfs4_flexfile_layoutreturn_args *ff_args)
1996 {
1997         __be32 *p;
1998         int i;
1999
2000         p = xdr_reserve_space(xdr, 4);
2001         *p = cpu_to_be32(ff_args->num_dev);
2002         for (i = 0; i < ff_args->num_dev; i++)
2003                 ff_layout_encode_ff_iostat(xdr,
2004                                 &args->layout->plh_stateid,
2005                                 &ff_args->devinfo[i]);
2006 }
2007
2008 static void
2009 ff_layout_free_iostats_array(struct nfs42_layoutstat_devinfo *devinfo,
2010                 unsigned int num_entries)
2011 {
2012         unsigned int i;
2013
2014         for (i = 0; i < num_entries; i++) {
2015                 if (!devinfo[i].ld_private.ops)
2016                         continue;
2017                 if (!devinfo[i].ld_private.ops->free)
2018                         continue;
2019                 devinfo[i].ld_private.ops->free(&devinfo[i].ld_private);
2020         }
2021 }
2022
2023 static struct nfs4_deviceid_node *
2024 ff_layout_alloc_deviceid_node(struct nfs_server *server,
2025                               struct pnfs_device *pdev, gfp_t gfp_flags)
2026 {
2027         struct nfs4_ff_layout_ds *dsaddr;
2028
2029         dsaddr = nfs4_ff_alloc_deviceid_node(server, pdev, gfp_flags);
2030         if (!dsaddr)
2031                 return NULL;
2032         return &dsaddr->id_node;
2033 }
2034
2035 static void
2036 ff_layout_encode_layoutreturn(struct xdr_stream *xdr,
2037                 const void *voidargs,
2038                 const struct nfs4_xdr_opaque_data *ff_opaque)
2039 {
2040         const struct nfs4_layoutreturn_args *args = voidargs;
2041         struct nfs4_flexfile_layoutreturn_args *ff_args = ff_opaque->data;
2042         struct xdr_buf tmp_buf = {
2043                 .head = {
2044                         [0] = {
2045                                 .iov_base = page_address(ff_args->pages[0]),
2046                         },
2047                 },
2048                 .buflen = PAGE_SIZE,
2049         };
2050         struct xdr_stream tmp_xdr;
2051         __be32 *start;
2052
2053         dprintk("%s: Begin\n", __func__);
2054
2055         xdr_init_encode(&tmp_xdr, &tmp_buf, NULL);
2056
2057         ff_layout_encode_ioerr(&tmp_xdr, args, ff_args);
2058         ff_layout_encode_iostats_array(&tmp_xdr, args, ff_args);
2059
2060         start = xdr_reserve_space(xdr, 4);
2061         *start = cpu_to_be32(tmp_buf.len);
2062         xdr_write_pages(xdr, ff_args->pages, 0, tmp_buf.len);
2063
2064         dprintk("%s: Return\n", __func__);
2065 }
2066
2067 static void
2068 ff_layout_free_layoutreturn(struct nfs4_xdr_opaque_data *args)
2069 {
2070         struct nfs4_flexfile_layoutreturn_args *ff_args;
2071
2072         if (!args->data)
2073                 return;
2074         ff_args = args->data;
2075         args->data = NULL;
2076
2077         ff_layout_free_ds_ioerr(&ff_args->errors);
2078         ff_layout_free_iostats_array(ff_args->devinfo, ff_args->num_dev);
2079
2080         put_page(ff_args->pages[0]);
2081         kfree(ff_args);
2082 }
2083
2084 static const struct nfs4_xdr_opaque_ops layoutreturn_ops = {
2085         .encode = ff_layout_encode_layoutreturn,
2086         .free = ff_layout_free_layoutreturn,
2087 };
2088
2089 static int
2090 ff_layout_prepare_layoutreturn(struct nfs4_layoutreturn_args *args)
2091 {
2092         struct nfs4_flexfile_layoutreturn_args *ff_args;
2093         struct nfs4_flexfile_layout *ff_layout = FF_LAYOUT_FROM_HDR(args->layout);
2094
2095         ff_args = kmalloc(sizeof(*ff_args), GFP_KERNEL);
2096         if (!ff_args)
2097                 goto out_nomem;
2098         ff_args->pages[0] = alloc_page(GFP_KERNEL);
2099         if (!ff_args->pages[0])
2100                 goto out_nomem_free;
2101
2102         INIT_LIST_HEAD(&ff_args->errors);
2103         ff_args->num_errors = ff_layout_fetch_ds_ioerr(args->layout,
2104                         &args->range, &ff_args->errors,
2105                         FF_LAYOUTRETURN_MAXERR);
2106
2107         spin_lock(&args->inode->i_lock);
2108         ff_args->num_dev = ff_layout_mirror_prepare_stats(&ff_layout->generic_hdr,
2109                         &ff_args->devinfo[0], ARRAY_SIZE(ff_args->devinfo));
2110         spin_unlock(&args->inode->i_lock);
2111
2112         args->ld_private->ops = &layoutreturn_ops;
2113         args->ld_private->data = ff_args;
2114         return 0;
2115 out_nomem_free:
2116         kfree(ff_args);
2117 out_nomem:
2118         return -ENOMEM;
2119 }
2120
2121 static int
2122 ff_layout_ntop4(const struct sockaddr *sap, char *buf, const size_t buflen)
2123 {
2124         const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
2125
2126         return snprintf(buf, buflen, "%pI4", &sin->sin_addr);
2127 }
2128
2129 static size_t
2130 ff_layout_ntop6_noscopeid(const struct sockaddr *sap, char *buf,
2131                           const int buflen)
2132 {
2133         const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
2134         const struct in6_addr *addr = &sin6->sin6_addr;
2135
2136         /*
2137          * RFC 4291, Section 2.2.2
2138          *
2139          * Shorthanded ANY address
2140          */
2141         if (ipv6_addr_any(addr))
2142                 return snprintf(buf, buflen, "::");
2143
2144         /*
2145          * RFC 4291, Section 2.2.2
2146          *
2147          * Shorthanded loopback address
2148          */
2149         if (ipv6_addr_loopback(addr))
2150                 return snprintf(buf, buflen, "::1");
2151
2152         /*
2153          * RFC 4291, Section 2.2.3
2154          *
2155          * Special presentation address format for mapped v4
2156          * addresses.
2157          */
2158         if (ipv6_addr_v4mapped(addr))
2159                 return snprintf(buf, buflen, "::ffff:%pI4",
2160                                         &addr->s6_addr32[3]);
2161
2162         /*
2163          * RFC 4291, Section 2.2.1
2164          */
2165         return snprintf(buf, buflen, "%pI6c", addr);
2166 }
2167
2168 /* Derived from rpc_sockaddr2uaddr */
2169 static void
2170 ff_layout_encode_netaddr(struct xdr_stream *xdr, struct nfs4_pnfs_ds_addr *da)
2171 {
2172         struct sockaddr *sap = (struct sockaddr *)&da->da_addr;
2173         char portbuf[RPCBIND_MAXUADDRPLEN];
2174         char addrbuf[RPCBIND_MAXUADDRLEN];
2175         char *netid;
2176         unsigned short port;
2177         int len, netid_len;
2178         __be32 *p;
2179
2180         switch (sap->sa_family) {
2181         case AF_INET:
2182                 if (ff_layout_ntop4(sap, addrbuf, sizeof(addrbuf)) == 0)
2183                         return;
2184                 port = ntohs(((struct sockaddr_in *)sap)->sin_port);
2185                 netid = "tcp";
2186                 netid_len = 3;
2187                 break;
2188         case AF_INET6:
2189                 if (ff_layout_ntop6_noscopeid(sap, addrbuf, sizeof(addrbuf)) == 0)
2190                         return;
2191                 port = ntohs(((struct sockaddr_in6 *)sap)->sin6_port);
2192                 netid = "tcp6";
2193                 netid_len = 4;
2194                 break;
2195         default:
2196                 /* we only support tcp and tcp6 */
2197                 WARN_ON_ONCE(1);
2198                 return;
2199         }
2200
2201         snprintf(portbuf, sizeof(portbuf), ".%u.%u", port >> 8, port & 0xff);
2202         len = strlcat(addrbuf, portbuf, sizeof(addrbuf));
2203
2204         p = xdr_reserve_space(xdr, 4 + netid_len);
2205         xdr_encode_opaque(p, netid, netid_len);
2206
2207         p = xdr_reserve_space(xdr, 4 + len);
2208         xdr_encode_opaque(p, addrbuf, len);
2209 }
2210
2211 static void
2212 ff_layout_encode_nfstime(struct xdr_stream *xdr,
2213                          ktime_t t)
2214 {
2215         struct timespec64 ts;
2216         __be32 *p;
2217
2218         p = xdr_reserve_space(xdr, 12);
2219         ts = ktime_to_timespec64(t);
2220         p = xdr_encode_hyper(p, ts.tv_sec);
2221         *p++ = cpu_to_be32(ts.tv_nsec);
2222 }
2223
2224 static void
2225 ff_layout_encode_io_latency(struct xdr_stream *xdr,
2226                             struct nfs4_ff_io_stat *stat)
2227 {
2228         __be32 *p;
2229
2230         p = xdr_reserve_space(xdr, 5 * 8);
2231         p = xdr_encode_hyper(p, stat->ops_requested);
2232         p = xdr_encode_hyper(p, stat->bytes_requested);
2233         p = xdr_encode_hyper(p, stat->ops_completed);
2234         p = xdr_encode_hyper(p, stat->bytes_completed);
2235         p = xdr_encode_hyper(p, stat->bytes_not_delivered);
2236         ff_layout_encode_nfstime(xdr, stat->total_busy_time);
2237         ff_layout_encode_nfstime(xdr, stat->aggregate_completion_time);
2238 }
2239
2240 static void
2241 ff_layout_encode_ff_layoutupdate(struct xdr_stream *xdr,
2242                               const struct nfs42_layoutstat_devinfo *devinfo,
2243                               struct nfs4_ff_layout_mirror *mirror)
2244 {
2245         struct nfs4_pnfs_ds_addr *da;
2246         struct nfs4_pnfs_ds *ds = mirror->mirror_ds->ds;
2247         struct nfs_fh *fh = &mirror->fh_versions[0];
2248         __be32 *p;
2249
2250         da = list_first_entry(&ds->ds_addrs, struct nfs4_pnfs_ds_addr, da_node);
2251         dprintk("%s: DS %s: encoding address %s\n",
2252                 __func__, ds->ds_remotestr, da->da_remotestr);
2253         /* netaddr4 */
2254         ff_layout_encode_netaddr(xdr, da);
2255         /* nfs_fh4 */
2256         p = xdr_reserve_space(xdr, 4 + fh->size);
2257         xdr_encode_opaque(p, fh->data, fh->size);
2258         /* ff_io_latency4 read */
2259         spin_lock(&mirror->lock);
2260         ff_layout_encode_io_latency(xdr, &mirror->read_stat.io_stat);
2261         /* ff_io_latency4 write */
2262         ff_layout_encode_io_latency(xdr, &mirror->write_stat.io_stat);
2263         spin_unlock(&mirror->lock);
2264         /* nfstime4 */
2265         ff_layout_encode_nfstime(xdr, ktime_sub(ktime_get(), mirror->start_time));
2266         /* bool */
2267         p = xdr_reserve_space(xdr, 4);
2268         *p = cpu_to_be32(false);
2269 }
2270
2271 static void
2272 ff_layout_encode_layoutstats(struct xdr_stream *xdr, const void *args,
2273                              const struct nfs4_xdr_opaque_data *opaque)
2274 {
2275         struct nfs42_layoutstat_devinfo *devinfo = container_of(opaque,
2276                         struct nfs42_layoutstat_devinfo, ld_private);
2277         __be32 *start;
2278
2279         /* layoutupdate length */
2280         start = xdr_reserve_space(xdr, 4);
2281         ff_layout_encode_ff_layoutupdate(xdr, devinfo, opaque->data);
2282
2283         *start = cpu_to_be32((xdr->p - start - 1) * 4);
2284 }
2285
2286 static void
2287 ff_layout_free_layoutstats(struct nfs4_xdr_opaque_data *opaque)
2288 {
2289         struct nfs4_ff_layout_mirror *mirror = opaque->data;
2290
2291         ff_layout_put_mirror(mirror);
2292 }
2293
2294 static const struct nfs4_xdr_opaque_ops layoutstat_ops = {
2295         .encode = ff_layout_encode_layoutstats,
2296         .free   = ff_layout_free_layoutstats,
2297 };
2298
2299 static int
2300 ff_layout_mirror_prepare_stats(struct pnfs_layout_hdr *lo,
2301                                struct nfs42_layoutstat_devinfo *devinfo,
2302                                int dev_limit)
2303 {
2304         struct nfs4_flexfile_layout *ff_layout = FF_LAYOUT_FROM_HDR(lo);
2305         struct nfs4_ff_layout_mirror *mirror;
2306         struct nfs4_deviceid_node *dev;
2307         int i = 0;
2308
2309         list_for_each_entry(mirror, &ff_layout->mirrors, mirrors) {
2310                 if (i >= dev_limit)
2311                         break;
2312                 if (IS_ERR_OR_NULL(mirror->mirror_ds))
2313                         continue;
2314                 if (!test_and_clear_bit(NFS4_FF_MIRROR_STAT_AVAIL, &mirror->flags))
2315                         continue;
2316                 /* mirror refcount put in cleanup_layoutstats */
2317                 if (!atomic_inc_not_zero(&mirror->ref))
2318                         continue;
2319                 dev = &mirror->mirror_ds->id_node;
2320                 memcpy(&devinfo->dev_id, &dev->deviceid, NFS4_DEVICEID4_SIZE);
2321                 devinfo->offset = 0;
2322                 devinfo->length = NFS4_MAX_UINT64;
2323                 spin_lock(&mirror->lock);
2324                 devinfo->read_count = mirror->read_stat.io_stat.ops_completed;
2325                 devinfo->read_bytes = mirror->read_stat.io_stat.bytes_completed;
2326                 devinfo->write_count = mirror->write_stat.io_stat.ops_completed;
2327                 devinfo->write_bytes = mirror->write_stat.io_stat.bytes_completed;
2328                 spin_unlock(&mirror->lock);
2329                 devinfo->layout_type = LAYOUT_FLEX_FILES;
2330                 devinfo->ld_private.ops = &layoutstat_ops;
2331                 devinfo->ld_private.data = mirror;
2332
2333                 devinfo++;
2334                 i++;
2335         }
2336         return i;
2337 }
2338
2339 static int
2340 ff_layout_prepare_layoutstats(struct nfs42_layoutstat_args *args)
2341 {
2342         struct nfs4_flexfile_layout *ff_layout;
2343         const int dev_count = PNFS_LAYOUTSTATS_MAXDEV;
2344
2345         /* For now, send at most PNFS_LAYOUTSTATS_MAXDEV statistics */
2346         args->devinfo = kmalloc_array(dev_count, sizeof(*args->devinfo), GFP_NOIO);
2347         if (!args->devinfo)
2348                 return -ENOMEM;
2349
2350         spin_lock(&args->inode->i_lock);
2351         ff_layout = FF_LAYOUT_FROM_HDR(NFS_I(args->inode)->layout);
2352         args->num_dev = ff_layout_mirror_prepare_stats(&ff_layout->generic_hdr,
2353                         &args->devinfo[0], dev_count);
2354         spin_unlock(&args->inode->i_lock);
2355         if (!args->num_dev) {
2356                 kfree(args->devinfo);
2357                 args->devinfo = NULL;
2358                 return -ENOENT;
2359         }
2360
2361         return 0;
2362 }
2363
2364 static int
2365 ff_layout_set_layoutdriver(struct nfs_server *server,
2366                 const struct nfs_fh *dummy)
2367 {
2368 #if IS_ENABLED(CONFIG_NFS_V4_2)
2369         server->caps |= NFS_CAP_LAYOUTSTATS;
2370 #endif
2371         return 0;
2372 }
2373
2374 static struct pnfs_layoutdriver_type flexfilelayout_type = {
2375         .id                     = LAYOUT_FLEX_FILES,
2376         .name                   = "LAYOUT_FLEX_FILES",
2377         .owner                  = THIS_MODULE,
2378         .set_layoutdriver       = ff_layout_set_layoutdriver,
2379         .alloc_layout_hdr       = ff_layout_alloc_layout_hdr,
2380         .free_layout_hdr        = ff_layout_free_layout_hdr,
2381         .alloc_lseg             = ff_layout_alloc_lseg,
2382         .free_lseg              = ff_layout_free_lseg,
2383         .add_lseg               = ff_layout_add_lseg,
2384         .pg_read_ops            = &ff_layout_pg_read_ops,
2385         .pg_write_ops           = &ff_layout_pg_write_ops,
2386         .get_ds_info            = ff_layout_get_ds_info,
2387         .free_deviceid_node     = ff_layout_free_deviceid_node,
2388         .mark_request_commit    = pnfs_layout_mark_request_commit,
2389         .clear_request_commit   = pnfs_generic_clear_request_commit,
2390         .scan_commit_lists      = pnfs_generic_scan_commit_lists,
2391         .recover_commit_reqs    = pnfs_generic_recover_commit_reqs,
2392         .commit_pagelist        = ff_layout_commit_pagelist,
2393         .read_pagelist          = ff_layout_read_pagelist,
2394         .write_pagelist         = ff_layout_write_pagelist,
2395         .alloc_deviceid_node    = ff_layout_alloc_deviceid_node,
2396         .prepare_layoutreturn   = ff_layout_prepare_layoutreturn,
2397         .sync                   = pnfs_nfs_generic_sync,
2398         .prepare_layoutstats    = ff_layout_prepare_layoutstats,
2399 };
2400
2401 static int __init nfs4flexfilelayout_init(void)
2402 {
2403         printk(KERN_INFO "%s: NFSv4 Flexfile Layout Driver Registering...\n",
2404                __func__);
2405         if (!ff_zero_group) {
2406                 ff_zero_group = groups_alloc(0);
2407                 if (!ff_zero_group)
2408                         return -ENOMEM;
2409         }
2410         return pnfs_register_layoutdriver(&flexfilelayout_type);
2411 }
2412
2413 static void __exit nfs4flexfilelayout_exit(void)
2414 {
2415         printk(KERN_INFO "%s: NFSv4 Flexfile Layout Driver Unregistering...\n",
2416                __func__);
2417         pnfs_unregister_layoutdriver(&flexfilelayout_type);
2418         if (ff_zero_group) {
2419                 put_group_info(ff_zero_group);
2420                 ff_zero_group = NULL;
2421         }
2422 }
2423
2424 MODULE_ALIAS("nfs-layouttype4-4");
2425
2426 MODULE_LICENSE("GPL");
2427 MODULE_DESCRIPTION("The NFSv4 flexfile layout driver");
2428
2429 module_init(nfs4flexfilelayout_init);
2430 module_exit(nfs4flexfilelayout_exit);