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         static const ktime_t notime = {0};
 623         s64 report_interval = FF_LAYOUTSTATS_REPORT_INTERVAL;
 624         struct nfs4_flexfile_layout *ffl = FF_LAYOUT_FROM_HDR(mirror->layout);
 625
 626         nfs4_ff_start_busy_timer(&layoutstat->busy_timer, now);
 627         if (ktime_equal(mirror->start_time, notime))
 628                 mirror->start_time = now;
 629         if (mirror->report_interval != 0)
 630                 report_interval = (s64)mirror->report_interval * 1000LL;
 631         else if (layoutstats_timer != 0)
 632                 report_interval = (s64)layoutstats_timer * 1000LL;
 633         if (ktime_to_ms(ktime_sub(now, ffl->last_report_time)) >=
 634                         report_interval) {
 635                 ffl->last_report_time = now;
 636                 return true;
 637         }
 638
 639         return false;
 640 }
 641
 642 static void
 643 nfs4_ff_layout_stat_io_update_requested(struct nfs4_ff_layoutstat *layoutstat,
 644                 __u64 requested)
 645 {
 646         struct nfs4_ff_io_stat *iostat = &layoutstat->io_stat;
 647
 648         iostat->ops_requested++;
 649         iostat->bytes_requested += requested;
 650 }
 651
 652 static void
 653 nfs4_ff_layout_stat_io_update_completed(struct nfs4_ff_layoutstat *layoutstat,
 654                 __u64 requested,
 655                 __u64 completed,
 656                 ktime_t time_completed,
 657                 ktime_t time_started)
 658 {
 659         struct nfs4_ff_io_stat *iostat = &layoutstat->io_stat;
 660         ktime_t completion_time = ktime_sub(time_completed, time_started);
 661         ktime_t timer;
 662
 663         iostat->ops_completed++;
 664         iostat->bytes_completed += completed;
 665         iostat->bytes_not_delivered += requested - completed;
 666
 667         timer = nfs4_ff_end_busy_timer(&layoutstat->busy_timer, time_completed);
 668         iostat->total_busy_time =
 669                         ktime_add(iostat->total_busy_time, timer);
 670         iostat->aggregate_completion_time =
 671                         ktime_add(iostat->aggregate_completion_time,
 672                                         completion_time);
 673 }
 674
 675 static void
 676 nfs4_ff_layout_stat_io_start_read(struct inode *inode,
 677                 struct nfs4_ff_layout_mirror *mirror,
 678                 __u64 requested, ktime_t now)
 679 {
 680         bool report;
 681
 682         spin_lock(&mirror->lock);
 683         report = nfs4_ff_layoutstat_start_io(mirror, &mirror->read_stat, now);
 684         nfs4_ff_layout_stat_io_update_requested(&mirror->read_stat, requested);
 685         set_bit(NFS4_FF_MIRROR_STAT_AVAIL, &mirror->flags);
 686         spin_unlock(&mirror->lock);
 687
 688         if (report)
 689                 pnfs_report_layoutstat(inode, GFP_KERNEL);
 690 }
 691
 692 static void
 693 nfs4_ff_layout_stat_io_end_read(struct rpc_task *task,
 694                 struct nfs4_ff_layout_mirror *mirror,
 695                 __u64 requested,
 696                 __u64 completed)
 697 {
 698         spin_lock(&mirror->lock);
 699         nfs4_ff_layout_stat_io_update_completed(&mirror->read_stat,
 700                         requested, completed,
 701                         ktime_get(), task->tk_start);
 702         set_bit(NFS4_FF_MIRROR_STAT_AVAIL, &mirror->flags);
 703         spin_unlock(&mirror->lock);
 704 }
 705
 706 static void
 707 nfs4_ff_layout_stat_io_start_write(struct inode *inode,
 708                 struct nfs4_ff_layout_mirror *mirror,
 709                 __u64 requested, ktime_t now)
 710 {
 711         bool report;
 712
 713         spin_lock(&mirror->lock);
 714         report = nfs4_ff_layoutstat_start_io(mirror , &mirror->write_stat, now);
 715         nfs4_ff_layout_stat_io_update_requested(&mirror->write_stat, requested);
 716         set_bit(NFS4_FF_MIRROR_STAT_AVAIL, &mirror->flags);
 717         spin_unlock(&mirror->lock);
 718
 719         if (report)
 720                 pnfs_report_layoutstat(inode, GFP_NOIO);
 721 }
 722
 723 static void
 724 nfs4_ff_layout_stat_io_end_write(struct rpc_task *task,
 725                 struct nfs4_ff_layout_mirror *mirror,
 726                 __u64 requested,
 727                 __u64 completed,
 728                 enum nfs3_stable_how committed)
 729 {
 730         if (committed == NFS_UNSTABLE)
 731                 requested = completed = 0;
 732
 733         spin_lock(&mirror->lock);
 734         nfs4_ff_layout_stat_io_update_completed(&mirror->write_stat,
 735                         requested, completed, ktime_get(), task->tk_start);
 736         set_bit(NFS4_FF_MIRROR_STAT_AVAIL, &mirror->flags);
 737         spin_unlock(&mirror->lock);
 738 }
 739
 740 static int
 741 ff_layout_alloc_commit_info(struct pnfs_layout_segment *lseg,
 742                             struct nfs_commit_info *cinfo,
 743                             gfp_t gfp_flags)
 744 {
 745         struct nfs4_ff_layout_segment *fls = FF_LAYOUT_LSEG(lseg);
 746         struct pnfs_commit_bucket *buckets;
 747         int size;
 748
 749         if (cinfo->ds->nbuckets != 0) {
 750                 /* This assumes there is only one RW lseg per file.
 751                  * To support multiple lseg per file, we need to
 752                  * change struct pnfs_commit_bucket to allow dynamic
 753                  * increasing nbuckets.
 754                  */
 755                 return 0;
 756         }
 757
 758         size = ff_layout_get_lseg_count(fls) * FF_LAYOUT_MIRROR_COUNT(lseg);
 759
 760         buckets = kcalloc(size, sizeof(struct pnfs_commit_bucket),
 761                           gfp_flags);
 762         if (!buckets)
 763                 return -ENOMEM;
 764         else {
 765                 int i;
 766
 767                 spin_lock(&cinfo->inode->i_lock);
 768                 if (cinfo->ds->nbuckets != 0)
 769                         kfree(buckets);
 770                 else {
 771                         cinfo->ds->buckets = buckets;
 772                         cinfo->ds->nbuckets = size;
 773                         for (i = 0; i < size; i++) {
 774                                 INIT_LIST_HEAD(&buckets[i].written);
 775                                 INIT_LIST_HEAD(&buckets[i].committing);
 776                                 /* mark direct verifier as unset */
 777                                 buckets[i].direct_verf.committed =
 778                                         NFS_INVALID_STABLE_HOW;
 779                         }
 780                 }
 781                 spin_unlock(&cinfo->inode->i_lock);
 782                 return 0;
 783         }
 784 }
 785
 786 static struct nfs4_pnfs_ds *
 787 ff_layout_choose_best_ds_for_read(struct pnfs_layout_segment *lseg,
 788                                   int start_idx,
 789                                   int *best_idx)
 790 {
 791         struct nfs4_ff_layout_segment *fls = FF_LAYOUT_LSEG(lseg);
 792         struct nfs4_pnfs_ds *ds;
 793         bool fail_return = false;
 794         int idx;
 795
 796         /* mirrors are sorted by efficiency */
 797         for (idx = start_idx; idx < fls->mirror_array_cnt; idx++) {
 798                 if (idx+1 == fls->mirror_array_cnt)
 799                         fail_return = true;
 800                 ds = nfs4_ff_layout_prepare_ds(lseg, idx, fail_return);
 801                 if (ds) {
 802                         *best_idx = idx;
 803                         return ds;
 804                 }
 805         }
 806
 807         return NULL;
 808 }
 809
 810 static void
 811 ff_layout_pg_get_read(struct nfs_pageio_descriptor *pgio,
 812                       struct nfs_page *req,
 813                       bool strict_iomode)
 814 {
 815 retry_strict:
 816         pnfs_put_lseg(pgio->pg_lseg);
 817         pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
 818                                            req->wb_context,
 819                                            0,
 820                                            NFS4_MAX_UINT64,
 821                                            IOMODE_READ,
 822                                            strict_iomode,
 823                                            GFP_KERNEL);
 824         if (IS_ERR(pgio->pg_lseg)) {
 825                 pgio->pg_error = PTR_ERR(pgio->pg_lseg);
 826                 pgio->pg_lseg = NULL;
 827         }
 828
 829         /* If we don't have checking, do get a IOMODE_RW
 830          * segment, and the server wants to avoid READs
 831          * there, then retry!
 832          */
 833         if (pgio->pg_lseg && !strict_iomode &&
 834             ff_layout_avoid_read_on_rw(pgio->pg_lseg)) {
 835                 strict_iomode = true;
 836                 goto retry_strict;
 837         }
 838 }
 839
 840 static void
 841 ff_layout_pg_init_read(struct nfs_pageio_descriptor *pgio,
 842                         struct nfs_page *req)
 843 {
 844         struct nfs_pgio_mirror *pgm;
 845         struct nfs4_ff_layout_mirror *mirror;
 846         struct nfs4_pnfs_ds *ds;
 847         int ds_idx;
 848
 849 retry:
 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         if (!pgio->pg_lseg) {
 899                 pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
 900                                                    req->wb_context,
 901                                                    0,
 902                                                    NFS4_MAX_UINT64,
 903                                                    IOMODE_RW,
 904                                                    false,
 905                                                    GFP_NOFS);
 906                 if (IS_ERR(pgio->pg_lseg)) {
 907                         pgio->pg_error = PTR_ERR(pgio->pg_lseg);
 908                         pgio->pg_lseg = NULL;
 909                         return;
 910                 }
 911         }
 912         /* If no lseg, fall back to write through mds */
 913         if (pgio->pg_lseg == NULL)
 914                 goto out_mds;
 915
 916         nfs_init_cinfo(&cinfo, pgio->pg_inode, pgio->pg_dreq);
 917         status = ff_layout_alloc_commit_info(pgio->pg_lseg, &cinfo, GFP_NOFS);
 918         if (status < 0)
 919                 goto out_mds;
 920
 921         /* Use a direct mapping of ds_idx to pgio mirror_idx */
 922         if (WARN_ON_ONCE(pgio->pg_mirror_count !=
 923             FF_LAYOUT_MIRROR_COUNT(pgio->pg_lseg)))
 924                 goto out_mds;
 925
 926         for (i = 0; i < pgio->pg_mirror_count; i++) {
 927                 ds = nfs4_ff_layout_prepare_ds(pgio->pg_lseg, i, true);
 928                 if (!ds) {
 929                         if (!ff_layout_no_fallback_to_mds(pgio->pg_lseg))
 930                                 goto out_mds;
 931                         pnfs_put_lseg(pgio->pg_lseg);
 932                         pgio->pg_lseg = NULL;
 933                         /* Sleep for 1 second before retrying */
 934                         ssleep(1);
 935                         goto retry;
 936                 }
 937                 pgm = &pgio->pg_mirrors[i];
 938                 mirror = FF_LAYOUT_COMP(pgio->pg_lseg, i);
 939                 pgm->pg_bsize = mirror->mirror_ds->ds_versions[0].wsize;
 940         }
 941
 942         return;
 943
 944 out_mds:
 945         pnfs_put_lseg(pgio->pg_lseg);
 946         pgio->pg_lseg = NULL;
 947         nfs_pageio_reset_write_mds(pgio);
 948 }
 949
 950 static unsigned int
 951 ff_layout_pg_get_mirror_count_write(struct nfs_pageio_descriptor *pgio,
 952                                     struct nfs_page *req)
 953 {
 954         if (!pgio->pg_lseg) {
 955                 pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
 956                                                    req->wb_context,
 957                                                    0,
 958                                                    NFS4_MAX_UINT64,
 959                                                    IOMODE_RW,
 960                                                    false,
 961                                                    GFP_NOFS);
 962                 if (IS_ERR(pgio->pg_lseg)) {
 963                         pgio->pg_error = PTR_ERR(pgio->pg_lseg);
 964                         pgio->pg_lseg = NULL;
 965                         goto out;
 966                 }
 967         }
 968         if (pgio->pg_lseg)
 969                 return FF_LAYOUT_MIRROR_COUNT(pgio->pg_lseg);
 970
 971         /* no lseg means that pnfs is not in use, so no mirroring here */
 972         nfs_pageio_reset_write_mds(pgio);
 973 out:
 974         return 1;
 975 }
 976
 977 static const struct nfs_pageio_ops ff_layout_pg_read_ops = {
 978         .pg_init = ff_layout_pg_init_read,
 979         .pg_test = pnfs_generic_pg_test,
 980         .pg_doio = pnfs_generic_pg_readpages,
 981         .pg_cleanup = pnfs_generic_pg_cleanup,
 982 };
 983
 984 static const struct nfs_pageio_ops ff_layout_pg_write_ops = {
 985         .pg_init = ff_layout_pg_init_write,
 986         .pg_test = pnfs_generic_pg_test,
 987         .pg_doio = pnfs_generic_pg_writepages,
 988         .pg_get_mirror_count = ff_layout_pg_get_mirror_count_write,
 989         .pg_cleanup = pnfs_generic_pg_cleanup,
 990 };
 991
 992 static void ff_layout_reset_write(struct nfs_pgio_header *hdr, bool retry_pnfs)
 993 {
 994         struct rpc_task *task = &hdr->task;
 995
 996         pnfs_layoutcommit_inode(hdr->inode, false);
 997
 998         if (retry_pnfs) {
 999                 dprintk("%s Reset task %5u for i/o through pNFS "
1000                         "(req %s/%llu, %u bytes @ offset %llu)\n", __func__,
1001                         hdr->task.tk_pid,
1002                         hdr->inode->i_sb->s_id,
1003                         (unsigned long long)NFS_FILEID(hdr->inode),
1004                         hdr->args.count,
1005                         (unsigned long long)hdr->args.offset);
1006
1007                 hdr->completion_ops->reschedule_io(hdr);
1008                 return;
1009         }
1010
1011         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
1012                 dprintk("%s Reset task %5u for i/o through MDS "
1013                         "(req %s/%llu, %u bytes @ offset %llu)\n", __func__,
1014                         hdr->task.tk_pid,
1015                         hdr->inode->i_sb->s_id,
1016                         (unsigned long long)NFS_FILEID(hdr->inode),
1017                         hdr->args.count,
1018                         (unsigned long long)hdr->args.offset);
1019
1020                 task->tk_status = pnfs_write_done_resend_to_mds(hdr);
1021         }
1022 }
1023
1024 static void ff_layout_reset_read(struct nfs_pgio_header *hdr)
1025 {
1026         struct rpc_task *task = &hdr->task;
1027
1028         pnfs_layoutcommit_inode(hdr->inode, false);
1029
1030         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
1031                 dprintk("%s Reset task %5u for i/o through MDS "
1032                         "(req %s/%llu, %u bytes @ offset %llu)\n", __func__,
1033                         hdr->task.tk_pid,
1034                         hdr->inode->i_sb->s_id,
1035                         (unsigned long long)NFS_FILEID(hdr->inode),
1036                         hdr->args.count,
1037                         (unsigned long long)hdr->args.offset);
1038
1039                 task->tk_status = pnfs_read_done_resend_to_mds(hdr);
1040         }
1041 }
1042
1043 static int ff_layout_async_handle_error_v4(struct rpc_task *task,
1044                                            struct nfs4_state *state,
1045                                            struct nfs_client *clp,
1046                                            struct pnfs_layout_segment *lseg,
1047                                            int idx)
1048 {
1049         struct pnfs_layout_hdr *lo = lseg->pls_layout;
1050         struct inode *inode = lo->plh_inode;
1051         struct nfs_server *mds_server = NFS_SERVER(inode);
1052
1053         struct nfs4_deviceid_node *devid = FF_LAYOUT_DEVID_NODE(lseg, idx);
1054         struct nfs_client *mds_client = mds_server->nfs_client;
1055         struct nfs4_slot_table *tbl = &clp->cl_session->fc_slot_table;
1056
1057         if (task->tk_status >= 0)
1058                 return 0;
1059
1060         switch (task->tk_status) {
1061         /* MDS state errors */
1062         case -NFS4ERR_DELEG_REVOKED:
1063         case -NFS4ERR_ADMIN_REVOKED:
1064         case -NFS4ERR_BAD_STATEID:
1065                 if (state == NULL)
1066                         break;
1067                 nfs_remove_bad_delegation(state->inode, NULL);
1068         case -NFS4ERR_OPENMODE:
1069                 if (state == NULL)
1070                         break;
1071                 if (nfs4_schedule_stateid_recovery(mds_server, state) < 0)
1072                         goto out_bad_stateid;
1073                 goto wait_on_recovery;
1074         case -NFS4ERR_EXPIRED:
1075                 if (state != NULL) {
1076                         if (nfs4_schedule_stateid_recovery(mds_server, state) < 0)
1077                                 goto out_bad_stateid;
1078                 }
1079                 nfs4_schedule_lease_recovery(mds_client);
1080                 goto wait_on_recovery;
1081         /* DS session errors */
1082         case -NFS4ERR_BADSESSION:
1083         case -NFS4ERR_BADSLOT:
1084         case -NFS4ERR_BAD_HIGH_SLOT:
1085         case -NFS4ERR_DEADSESSION:
1086         case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1087         case -NFS4ERR_SEQ_FALSE_RETRY:
1088         case -NFS4ERR_SEQ_MISORDERED:
1089                 dprintk("%s ERROR %d, Reset session. Exchangeid "
1090                         "flags 0x%x\n", __func__, task->tk_status,
1091                         clp->cl_exchange_flags);
1092                 nfs4_schedule_session_recovery(clp->cl_session, task->tk_status);
1093                 break;
1094         case -NFS4ERR_DELAY:
1095         case -NFS4ERR_GRACE:
1096                 rpc_delay(task, FF_LAYOUT_POLL_RETRY_MAX);
1097                 break;
1098         case -NFS4ERR_RETRY_UNCACHED_REP:
1099                 break;
1100         /* Invalidate Layout errors */
1101         case -NFS4ERR_PNFS_NO_LAYOUT:
1102         case -ESTALE:           /* mapped NFS4ERR_STALE */
1103         case -EBADHANDLE:       /* mapped NFS4ERR_BADHANDLE */
1104         case -EISDIR:           /* mapped NFS4ERR_ISDIR */
1105         case -NFS4ERR_FHEXPIRED:
1106         case -NFS4ERR_WRONG_TYPE:
1107                 dprintk("%s Invalid layout error %d\n", __func__,
1108                         task->tk_status);
1109                 /*
1110                  * Destroy layout so new i/o will get a new layout.
1111                  * Layout will not be destroyed until all current lseg
1112                  * references are put. Mark layout as invalid to resend failed
1113                  * i/o and all i/o waiting on the slot table to the MDS until
1114                  * layout is destroyed and a new valid layout is obtained.
1115                  */
1116                 pnfs_destroy_layout(NFS_I(inode));
1117                 rpc_wake_up(&tbl->slot_tbl_waitq);
1118                 goto reset;
1119         /* RPC connection errors */
1120         case -ECONNREFUSED:
1121         case -EHOSTDOWN:
1122         case -EHOSTUNREACH:
1123         case -ENETUNREACH:
1124         case -EIO:
1125         case -ETIMEDOUT:
1126         case -EPIPE:
1127                 dprintk("%s DS connection error %d\n", __func__,
1128                         task->tk_status);
1129                 nfs4_delete_deviceid(devid->ld, devid->nfs_client,
1130                                 &devid->deviceid);
1131                 rpc_wake_up(&tbl->slot_tbl_waitq);
1132                 /* fall through */
1133         default:
1134                 if (ff_layout_avoid_mds_available_ds(lseg))
1135                         return -NFS4ERR_RESET_TO_PNFS;
1136 reset:
1137                 dprintk("%s Retry through MDS. Error %d\n", __func__,
1138                         task->tk_status);
1139                 return -NFS4ERR_RESET_TO_MDS;
1140         }
1141 out:
1142         task->tk_status = 0;
1143         return -EAGAIN;
1144 out_bad_stateid:
1145         task->tk_status = -EIO;
1146         return 0;
1147 wait_on_recovery:
1148         rpc_sleep_on(&mds_client->cl_rpcwaitq, task, NULL);
1149         if (test_bit(NFS4CLNT_MANAGER_RUNNING, &mds_client->cl_state) == 0)
1150                 rpc_wake_up_queued_task(&mds_client->cl_rpcwaitq, task);
1151         goto out;
1152 }
1153
1154 /* Retry all errors through either pNFS or MDS except for -EJUKEBOX */
1155 static int ff_layout_async_handle_error_v3(struct rpc_task *task,
1156                                            struct pnfs_layout_segment *lseg,
1157                                            int idx)
1158 {
1159         struct nfs4_deviceid_node *devid = FF_LAYOUT_DEVID_NODE(lseg, idx);
1160
1161         if (task->tk_status >= 0)
1162                 return 0;
1163
1164         switch (task->tk_status) {
1165         /* File access problems. Don't mark the device as unavailable */
1166         case -EACCES:
1167         case -ESTALE:
1168         case -EISDIR:
1169         case -EBADHANDLE:
1170         case -ELOOP:
1171         case -ENOSPC:
1172                 break;
1173         case -EJUKEBOX:
1174                 nfs_inc_stats(lseg->pls_layout->plh_inode, NFSIOS_DELAY);
1175                 goto out_retry;
1176         default:
1177                 dprintk("%s DS connection error %d\n", __func__,
1178                         task->tk_status);
1179                 nfs4_delete_deviceid(devid->ld, devid->nfs_client,
1180                                 &devid->deviceid);
1181         }
1182         /* FIXME: Need to prevent infinite looping here. */
1183         return -NFS4ERR_RESET_TO_PNFS;
1184 out_retry:
1185         task->tk_status = 0;
1186         rpc_restart_call_prepare(task);
1187         rpc_delay(task, NFS_JUKEBOX_RETRY_TIME);
1188         return -EAGAIN;
1189 }
1190
1191 static int ff_layout_async_handle_error(struct rpc_task *task,
1192                                         struct nfs4_state *state,
1193                                         struct nfs_client *clp,
1194                                         struct pnfs_layout_segment *lseg,
1195                                         int idx)
1196 {
1197         int vers = clp->cl_nfs_mod->rpc_vers->number;
1198
1199         switch (vers) {
1200         case 3:
1201                 return ff_layout_async_handle_error_v3(task, lseg, idx);
1202         case 4:
1203                 return ff_layout_async_handle_error_v4(task, state, clp,
1204                                                        lseg, idx);
1205         default:
1206                 /* should never happen */
1207                 WARN_ON_ONCE(1);
1208                 return 0;
1209         }
1210 }
1211
1212 static void ff_layout_io_track_ds_error(struct pnfs_layout_segment *lseg,
1213                                         int idx, u64 offset, u64 length,
1214                                         u32 status, int opnum, int error)
1215 {
1216         struct nfs4_ff_layout_mirror *mirror;
1217         int err;
1218
1219         if (status == 0) {
1220                 switch (error) {
1221                 case -ETIMEDOUT:
1222                 case -EPFNOSUPPORT:
1223                 case -EPROTONOSUPPORT:
1224                 case -EOPNOTSUPP:
1225                 case -ECONNREFUSED:
1226                 case -ECONNRESET:
1227                 case -EHOSTDOWN:
1228                 case -EHOSTUNREACH:
1229                 case -ENETUNREACH:
1230                 case -EADDRINUSE:
1231                 case -ENOBUFS:
1232                 case -EPIPE:
1233                 case -EPERM:
1234                         status = NFS4ERR_NXIO;
1235                         break;
1236                 case -EACCES:
1237                         status = NFS4ERR_ACCESS;
1238                         break;
1239                 default:
1240                         return;
1241                 }
1242         }
1243
1244         switch (status) {
1245         case NFS4ERR_DELAY:
1246         case NFS4ERR_GRACE:
1247                 return;
1248         default:
1249                 break;
1250         }
1251
1252         mirror = FF_LAYOUT_COMP(lseg, idx);
1253         err = ff_layout_track_ds_error(FF_LAYOUT_FROM_HDR(lseg->pls_layout),
1254                                        mirror, offset, length, status, opnum,
1255                                        GFP_NOIO);
1256         pnfs_error_mark_layout_for_return(lseg->pls_layout->plh_inode, lseg);
1257         dprintk("%s: err %d op %d status %u\n", __func__, err, opnum, status);
1258 }
1259
1260 /* NFS_PROTO call done callback routines */
1261 static int ff_layout_read_done_cb(struct rpc_task *task,
1262                                 struct nfs_pgio_header *hdr)
1263 {
1264         int err;
1265
1266         trace_nfs4_pnfs_read(hdr, task->tk_status);
1267         if (task->tk_status < 0)
1268                 ff_layout_io_track_ds_error(hdr->lseg, hdr->pgio_mirror_idx,
1269                                             hdr->args.offset, hdr->args.count,
1270                                             hdr->res.op_status, OP_READ,
1271                                             task->tk_status);
1272         err = ff_layout_async_handle_error(task, hdr->args.context->state,
1273                                            hdr->ds_clp, hdr->lseg,
1274                                            hdr->pgio_mirror_idx);
1275
1276         switch (err) {
1277         case -NFS4ERR_RESET_TO_PNFS:
1278                 if (ff_layout_choose_best_ds_for_read(hdr->lseg,
1279                                         hdr->pgio_mirror_idx + 1,
1280                                         &hdr->pgio_mirror_idx))
1281                         goto out_eagain;
1282                 ff_layout_read_record_layoutstats_done(task, hdr);
1283                 pnfs_read_resend_pnfs(hdr);
1284                 return task->tk_status;
1285         case -NFS4ERR_RESET_TO_MDS:
1286                 ff_layout_reset_read(hdr);
1287                 return task->tk_status;
1288         case -EAGAIN:
1289                 goto out_eagain;
1290         }
1291
1292         return 0;
1293 out_eagain:
1294         rpc_restart_call_prepare(task);
1295         return -EAGAIN;
1296 }
1297
1298 static bool
1299 ff_layout_need_layoutcommit(struct pnfs_layout_segment *lseg)
1300 {
1301         return !(FF_LAYOUT_LSEG(lseg)->flags & FF_FLAGS_NO_LAYOUTCOMMIT);
1302 }
1303
1304 /*
1305  * We reference the rpc_cred of the first WRITE that triggers the need for
1306  * a LAYOUTCOMMIT, and use it to send the layoutcommit compound.
1307  * rfc5661 is not clear about which credential should be used.
1308  *
1309  * Flexlayout client should treat DS replied FILE_SYNC as DATA_SYNC, so
1310  * to follow http://www.rfc-editor.org/errata_search.php?rfc=5661&eid=2751
1311  * we always send layoutcommit after DS writes.
1312  */
1313 static void
1314 ff_layout_set_layoutcommit(struct inode *inode,
1315                 struct pnfs_layout_segment *lseg,
1316                 loff_t end_offset)
1317 {
1318         if (!ff_layout_need_layoutcommit(lseg))
1319                 return;
1320
1321         pnfs_set_layoutcommit(inode, lseg, end_offset);
1322         dprintk("%s inode %lu pls_end_pos %llu\n", __func__, inode->i_ino,
1323                 (unsigned long long) NFS_I(inode)->layout->plh_lwb);
1324 }
1325
1326 static bool
1327 ff_layout_device_unavailable(struct pnfs_layout_segment *lseg, int idx)
1328 {
1329         /* No mirroring for now */
1330         struct nfs4_deviceid_node *node = FF_LAYOUT_DEVID_NODE(lseg, idx);
1331
1332         return ff_layout_test_devid_unavailable(node);
1333 }
1334
1335 static void ff_layout_read_record_layoutstats_start(struct rpc_task *task,
1336                 struct nfs_pgio_header *hdr)
1337 {
1338         if (test_and_set_bit(NFS_IOHDR_STAT, &hdr->flags))
1339                 return;
1340         nfs4_ff_layout_stat_io_start_read(hdr->inode,
1341                         FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
1342                         hdr->args.count,
1343                         task->tk_start);
1344 }
1345
1346 static void ff_layout_read_record_layoutstats_done(struct rpc_task *task,
1347                 struct nfs_pgio_header *hdr)
1348 {
1349         if (!test_and_clear_bit(NFS_IOHDR_STAT, &hdr->flags))
1350                 return;
1351         nfs4_ff_layout_stat_io_end_read(task,
1352                         FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
1353                         hdr->args.count,
1354                         hdr->res.count);
1355 }
1356
1357 static int ff_layout_read_prepare_common(struct rpc_task *task,
1358                                          struct nfs_pgio_header *hdr)
1359 {
1360         if (unlikely(test_bit(NFS_CONTEXT_BAD, &hdr->args.context->flags))) {
1361                 rpc_exit(task, -EIO);
1362                 return -EIO;
1363         }
1364         if (ff_layout_device_unavailable(hdr->lseg, hdr->pgio_mirror_idx)) {
1365                 rpc_exit(task, -EHOSTDOWN);
1366                 return -EAGAIN;
1367         }
1368
1369         ff_layout_read_record_layoutstats_start(task, hdr);
1370         return 0;
1371 }
1372
1373 /*
1374  * Call ops for the async read/write cases
1375  * In the case of dense layouts, the offset needs to be reset to its
1376  * original value.
1377  */
1378 static void ff_layout_read_prepare_v3(struct rpc_task *task, void *data)
1379 {
1380         struct nfs_pgio_header *hdr = data;
1381
1382         if (ff_layout_read_prepare_common(task, hdr))
1383                 return;
1384
1385         rpc_call_start(task);
1386 }
1387
1388 static int ff_layout_setup_sequence(struct nfs_client *ds_clp,
1389                                     struct nfs4_sequence_args *args,
1390                                     struct nfs4_sequence_res *res,
1391                                     struct rpc_task *task)
1392 {
1393         if (ds_clp->cl_session)
1394                 return nfs41_setup_sequence(ds_clp->cl_session,
1395                                            args,
1396                                            res,
1397                                            task);
1398         return nfs40_setup_sequence(ds_clp->cl_slot_tbl,
1399                                    args,
1400                                    res,
1401                                    task);
1402 }
1403
1404 static void ff_layout_read_prepare_v4(struct rpc_task *task, void *data)
1405 {
1406         struct nfs_pgio_header *hdr = data;
1407
1408         if (ff_layout_setup_sequence(hdr->ds_clp,
1409                                      &hdr->args.seq_args,
1410                                      &hdr->res.seq_res,
1411                                      task))
1412                 return;
1413
1414         if (ff_layout_read_prepare_common(task, hdr))
1415                 return;
1416
1417         if (nfs4_set_rw_stateid(&hdr->args.stateid, hdr->args.context,
1418                         hdr->args.lock_context, FMODE_READ) == -EIO)
1419                 rpc_exit(task, -EIO); /* lost lock, terminate I/O */
1420 }
1421
1422 static void ff_layout_read_call_done(struct rpc_task *task, void *data)
1423 {
1424         struct nfs_pgio_header *hdr = data;
1425
1426         dprintk("--> %s task->tk_status %d\n", __func__, task->tk_status);
1427
1428         if (test_bit(NFS_IOHDR_REDO, &hdr->flags) &&
1429             task->tk_status == 0) {
1430                 nfs4_sequence_done(task, &hdr->res.seq_res);
1431                 return;
1432         }
1433
1434         /* Note this may cause RPC to be resent */
1435         hdr->mds_ops->rpc_call_done(task, hdr);
1436 }
1437
1438 static void ff_layout_read_count_stats(struct rpc_task *task, void *data)
1439 {
1440         struct nfs_pgio_header *hdr = data;
1441
1442         ff_layout_read_record_layoutstats_done(task, hdr);
1443         rpc_count_iostats_metrics(task,
1444             &NFS_CLIENT(hdr->inode)->cl_metrics[NFSPROC4_CLNT_READ]);
1445 }
1446
1447 static void ff_layout_read_release(void *data)
1448 {
1449         struct nfs_pgio_header *hdr = data;
1450
1451         ff_layout_read_record_layoutstats_done(&hdr->task, hdr);
1452         pnfs_generic_rw_release(data);
1453 }
1454
1455
1456 static int ff_layout_write_done_cb(struct rpc_task *task,
1457                                 struct nfs_pgio_header *hdr)
1458 {
1459         loff_t end_offs = 0;
1460         int err;
1461
1462         trace_nfs4_pnfs_write(hdr, task->tk_status);
1463         if (task->tk_status < 0)
1464                 ff_layout_io_track_ds_error(hdr->lseg, hdr->pgio_mirror_idx,
1465                                             hdr->args.offset, hdr->args.count,
1466                                             hdr->res.op_status, OP_WRITE,
1467                                             task->tk_status);
1468         err = ff_layout_async_handle_error(task, hdr->args.context->state,
1469                                            hdr->ds_clp, hdr->lseg,
1470                                            hdr->pgio_mirror_idx);
1471
1472         switch (err) {
1473         case -NFS4ERR_RESET_TO_PNFS:
1474                 ff_layout_reset_write(hdr, true);
1475                 return task->tk_status;
1476         case -NFS4ERR_RESET_TO_MDS:
1477                 ff_layout_reset_write(hdr, false);
1478                 return task->tk_status;
1479         case -EAGAIN:
1480                 return -EAGAIN;
1481         }
1482
1483         if (hdr->res.verf->committed == NFS_FILE_SYNC ||
1484             hdr->res.verf->committed == NFS_DATA_SYNC)
1485                 end_offs = hdr->mds_offset + (loff_t)hdr->res.count;
1486
1487         /* Note: if the write is unstable, don't set end_offs until commit */
1488         ff_layout_set_layoutcommit(hdr->inode, hdr->lseg, end_offs);
1489
1490         /* zero out fattr since we don't care DS attr at all */
1491         hdr->fattr.valid = 0;
1492         if (task->tk_status >= 0)
1493                 nfs_writeback_update_inode(hdr);
1494
1495         return 0;
1496 }
1497
1498 static int ff_layout_commit_done_cb(struct rpc_task *task,
1499                                      struct nfs_commit_data *data)
1500 {
1501         int err;
1502
1503         trace_nfs4_pnfs_commit_ds(data, task->tk_status);
1504         if (task->tk_status < 0)
1505                 ff_layout_io_track_ds_error(data->lseg, data->ds_commit_index,
1506                                             data->args.offset, data->args.count,
1507                                             data->res.op_status, OP_COMMIT,
1508                                             task->tk_status);
1509         err = ff_layout_async_handle_error(task, NULL, data->ds_clp,
1510                                            data->lseg, data->ds_commit_index);
1511
1512         switch (err) {
1513         case -NFS4ERR_RESET_TO_PNFS:
1514                 pnfs_generic_prepare_to_resend_writes(data);
1515                 return -EAGAIN;
1516         case -NFS4ERR_RESET_TO_MDS:
1517                 pnfs_generic_prepare_to_resend_writes(data);
1518                 return -EAGAIN;
1519         case -EAGAIN:
1520                 rpc_restart_call_prepare(task);
1521                 return -EAGAIN;
1522         }
1523
1524         ff_layout_set_layoutcommit(data->inode, data->lseg, data->lwb);
1525
1526         return 0;
1527 }
1528
1529 static void ff_layout_write_record_layoutstats_start(struct rpc_task *task,
1530                 struct nfs_pgio_header *hdr)
1531 {
1532         if (test_and_set_bit(NFS_IOHDR_STAT, &hdr->flags))
1533                 return;
1534         nfs4_ff_layout_stat_io_start_write(hdr->inode,
1535                         FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
1536                         hdr->args.count,
1537                         task->tk_start);
1538 }
1539
1540 static void ff_layout_write_record_layoutstats_done(struct rpc_task *task,
1541                 struct nfs_pgio_header *hdr)
1542 {
1543         if (!test_and_clear_bit(NFS_IOHDR_STAT, &hdr->flags))
1544                 return;
1545         nfs4_ff_layout_stat_io_end_write(task,
1546                         FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
1547                         hdr->args.count, hdr->res.count,
1548                         hdr->res.verf->committed);
1549 }
1550
1551 static int ff_layout_write_prepare_common(struct rpc_task *task,
1552                                           struct nfs_pgio_header *hdr)
1553 {
1554         if (unlikely(test_bit(NFS_CONTEXT_BAD, &hdr->args.context->flags))) {
1555                 rpc_exit(task, -EIO);
1556                 return -EIO;
1557         }
1558
1559         if (ff_layout_device_unavailable(hdr->lseg, hdr->pgio_mirror_idx)) {
1560                 rpc_exit(task, -EHOSTDOWN);
1561                 return -EAGAIN;
1562         }
1563
1564         ff_layout_write_record_layoutstats_start(task, hdr);
1565         return 0;
1566 }
1567
1568 static void ff_layout_write_prepare_v3(struct rpc_task *task, void *data)
1569 {
1570         struct nfs_pgio_header *hdr = data;
1571
1572         if (ff_layout_write_prepare_common(task, hdr))
1573                 return;
1574
1575         rpc_call_start(task);
1576 }
1577
1578 static void ff_layout_write_prepare_v4(struct rpc_task *task, void *data)
1579 {
1580         struct nfs_pgio_header *hdr = data;
1581
1582         if (ff_layout_setup_sequence(hdr->ds_clp,
1583                                      &hdr->args.seq_args,
1584                                      &hdr->res.seq_res,
1585                                      task))
1586                 return;
1587
1588         if (ff_layout_write_prepare_common(task, hdr))
1589                 return;
1590
1591         if (nfs4_set_rw_stateid(&hdr->args.stateid, hdr->args.context,
1592                         hdr->args.lock_context, FMODE_WRITE) == -EIO)
1593                 rpc_exit(task, -EIO); /* lost lock, terminate I/O */
1594 }
1595
1596 static void ff_layout_write_call_done(struct rpc_task *task, void *data)
1597 {
1598         struct nfs_pgio_header *hdr = data;
1599
1600         if (test_bit(NFS_IOHDR_REDO, &hdr->flags) &&
1601             task->tk_status == 0) {
1602                 nfs4_sequence_done(task, &hdr->res.seq_res);
1603                 return;
1604         }
1605
1606         /* Note this may cause RPC to be resent */
1607         hdr->mds_ops->rpc_call_done(task, hdr);
1608 }
1609
1610 static void ff_layout_write_count_stats(struct rpc_task *task, void *data)
1611 {
1612         struct nfs_pgio_header *hdr = data;
1613
1614         ff_layout_write_record_layoutstats_done(task, hdr);
1615         rpc_count_iostats_metrics(task,
1616             &NFS_CLIENT(hdr->inode)->cl_metrics[NFSPROC4_CLNT_WRITE]);
1617 }
1618
1619 static void ff_layout_write_release(void *data)
1620 {
1621         struct nfs_pgio_header *hdr = data;
1622
1623         ff_layout_write_record_layoutstats_done(&hdr->task, hdr);
1624         pnfs_generic_rw_release(data);
1625 }
1626
1627 static void ff_layout_commit_record_layoutstats_start(struct rpc_task *task,
1628                 struct nfs_commit_data *cdata)
1629 {
1630         if (test_and_set_bit(NFS_IOHDR_STAT, &cdata->flags))
1631                 return;
1632         nfs4_ff_layout_stat_io_start_write(cdata->inode,
1633                         FF_LAYOUT_COMP(cdata->lseg, cdata->ds_commit_index),
1634                         0, task->tk_start);
1635 }
1636
1637 static void ff_layout_commit_record_layoutstats_done(struct rpc_task *task,
1638                 struct nfs_commit_data *cdata)
1639 {
1640         struct nfs_page *req;
1641         __u64 count = 0;
1642
1643         if (!test_and_clear_bit(NFS_IOHDR_STAT, &cdata->flags))
1644                 return;
1645
1646         if (task->tk_status == 0) {
1647                 list_for_each_entry(req, &cdata->pages, wb_list)
1648                         count += req->wb_bytes;
1649         }
1650         nfs4_ff_layout_stat_io_end_write(task,
1651                         FF_LAYOUT_COMP(cdata->lseg, cdata->ds_commit_index),
1652                         count, count, NFS_FILE_SYNC);
1653 }
1654
1655 static void ff_layout_commit_prepare_common(struct rpc_task *task,
1656                 struct nfs_commit_data *cdata)
1657 {
1658         ff_layout_commit_record_layoutstats_start(task, cdata);
1659 }
1660
1661 static void ff_layout_commit_prepare_v3(struct rpc_task *task, void *data)
1662 {
1663         ff_layout_commit_prepare_common(task, data);
1664         rpc_call_start(task);
1665 }
1666
1667 static void ff_layout_commit_prepare_v4(struct rpc_task *task, void *data)
1668 {
1669         struct nfs_commit_data *wdata = data;
1670
1671         if (ff_layout_setup_sequence(wdata->ds_clp,
1672                                  &wdata->args.seq_args,
1673                                  &wdata->res.seq_res,
1674                                  task))
1675                 return;
1676         ff_layout_commit_prepare_common(task, data);
1677 }
1678
1679 static void ff_layout_commit_done(struct rpc_task *task, void *data)
1680 {
1681         pnfs_generic_write_commit_done(task, data);
1682 }
1683
1684 static void ff_layout_commit_count_stats(struct rpc_task *task, void *data)
1685 {
1686         struct nfs_commit_data *cdata = data;
1687
1688         ff_layout_commit_record_layoutstats_done(task, cdata);
1689         rpc_count_iostats_metrics(task,
1690             &NFS_CLIENT(cdata->inode)->cl_metrics[NFSPROC4_CLNT_COMMIT]);
1691 }
1692
1693 static void ff_layout_commit_release(void *data)
1694 {
1695         struct nfs_commit_data *cdata = data;
1696
1697         ff_layout_commit_record_layoutstats_done(&cdata->task, cdata);
1698         pnfs_generic_commit_release(data);
1699 }
1700
1701 static const struct rpc_call_ops ff_layout_read_call_ops_v3 = {
1702         .rpc_call_prepare = ff_layout_read_prepare_v3,
1703         .rpc_call_done = ff_layout_read_call_done,
1704         .rpc_count_stats = ff_layout_read_count_stats,
1705         .rpc_release = ff_layout_read_release,
1706 };
1707
1708 static const struct rpc_call_ops ff_layout_read_call_ops_v4 = {
1709         .rpc_call_prepare = ff_layout_read_prepare_v4,
1710         .rpc_call_done = ff_layout_read_call_done,
1711         .rpc_count_stats = ff_layout_read_count_stats,
1712         .rpc_release = ff_layout_read_release,
1713 };
1714
1715 static const struct rpc_call_ops ff_layout_write_call_ops_v3 = {
1716         .rpc_call_prepare = ff_layout_write_prepare_v3,
1717         .rpc_call_done = ff_layout_write_call_done,
1718         .rpc_count_stats = ff_layout_write_count_stats,
1719         .rpc_release = ff_layout_write_release,
1720 };
1721
1722 static const struct rpc_call_ops ff_layout_write_call_ops_v4 = {
1723         .rpc_call_prepare = ff_layout_write_prepare_v4,
1724         .rpc_call_done = ff_layout_write_call_done,
1725         .rpc_count_stats = ff_layout_write_count_stats,
1726         .rpc_release = ff_layout_write_release,
1727 };
1728
1729 static const struct rpc_call_ops ff_layout_commit_call_ops_v3 = {
1730         .rpc_call_prepare = ff_layout_commit_prepare_v3,
1731         .rpc_call_done = ff_layout_commit_done,
1732         .rpc_count_stats = ff_layout_commit_count_stats,
1733         .rpc_release = ff_layout_commit_release,
1734 };
1735
1736 static const struct rpc_call_ops ff_layout_commit_call_ops_v4 = {
1737         .rpc_call_prepare = ff_layout_commit_prepare_v4,
1738         .rpc_call_done = ff_layout_commit_done,
1739         .rpc_count_stats = ff_layout_commit_count_stats,
1740         .rpc_release = ff_layout_commit_release,
1741 };
1742
1743 static enum pnfs_try_status
1744 ff_layout_read_pagelist(struct nfs_pgio_header *hdr)
1745 {
1746         struct pnfs_layout_segment *lseg = hdr->lseg;
1747         struct nfs4_pnfs_ds *ds;
1748         struct rpc_clnt *ds_clnt;
1749         struct rpc_cred *ds_cred;
1750         loff_t offset = hdr->args.offset;
1751         u32 idx = hdr->pgio_mirror_idx;
1752         int vers;
1753         struct nfs_fh *fh;
1754
1755         dprintk("--> %s ino %lu pgbase %u req %Zu@%llu\n",
1756                 __func__, hdr->inode->i_ino,
1757                 hdr->args.pgbase, (size_t)hdr->args.count, offset);
1758
1759         ds = nfs4_ff_layout_prepare_ds(lseg, idx, false);
1760         if (!ds)
1761                 goto out_failed;
1762
1763         ds_clnt = nfs4_ff_find_or_create_ds_client(lseg, idx, ds->ds_clp,
1764                                                    hdr->inode);
1765         if (IS_ERR(ds_clnt))
1766                 goto out_failed;
1767
1768         ds_cred = ff_layout_get_ds_cred(lseg, idx, hdr->cred);
1769         if (!ds_cred)
1770                 goto out_failed;
1771
1772         vers = nfs4_ff_layout_ds_version(lseg, idx);
1773
1774         dprintk("%s USE DS: %s cl_count %d vers %d\n", __func__,
1775                 ds->ds_remotestr, atomic_read(&ds->ds_clp->cl_count), vers);
1776
1777         hdr->pgio_done_cb = ff_layout_read_done_cb;
1778         atomic_inc(&ds->ds_clp->cl_count);
1779         hdr->ds_clp = ds->ds_clp;
1780         fh = nfs4_ff_layout_select_ds_fh(lseg, idx);
1781         if (fh)
1782                 hdr->args.fh = fh;
1783         /*
1784          * Note that if we ever decide to split across DSes,
1785          * then we may need to handle dense-like offsets.
1786          */
1787         hdr->args.offset = offset;
1788         hdr->mds_offset = offset;
1789
1790         /* Perform an asynchronous read to ds */
1791         nfs_initiate_pgio(ds_clnt, hdr, ds_cred, ds->ds_clp->rpc_ops,
1792                           vers == 3 ? &ff_layout_read_call_ops_v3 :
1793                                       &ff_layout_read_call_ops_v4,
1794                           0, RPC_TASK_SOFTCONN);
1795         put_rpccred(ds_cred);
1796         return PNFS_ATTEMPTED;
1797
1798 out_failed:
1799         if (ff_layout_avoid_mds_available_ds(lseg))
1800                 return PNFS_TRY_AGAIN;
1801         return PNFS_NOT_ATTEMPTED;
1802 }
1803
1804 /* Perform async writes. */
1805 static enum pnfs_try_status
1806 ff_layout_write_pagelist(struct nfs_pgio_header *hdr, int sync)
1807 {
1808         struct pnfs_layout_segment *lseg = hdr->lseg;
1809         struct nfs4_pnfs_ds *ds;
1810         struct rpc_clnt *ds_clnt;
1811         struct rpc_cred *ds_cred;
1812         loff_t offset = hdr->args.offset;
1813         int vers;
1814         struct nfs_fh *fh;
1815         int idx = hdr->pgio_mirror_idx;
1816
1817         ds = nfs4_ff_layout_prepare_ds(lseg, idx, true);
1818         if (!ds)
1819                 return PNFS_NOT_ATTEMPTED;
1820
1821         ds_clnt = nfs4_ff_find_or_create_ds_client(lseg, idx, ds->ds_clp,
1822                                                    hdr->inode);
1823         if (IS_ERR(ds_clnt))
1824                 return PNFS_NOT_ATTEMPTED;
1825
1826         ds_cred = ff_layout_get_ds_cred(lseg, idx, hdr->cred);
1827         if (!ds_cred)
1828                 return PNFS_NOT_ATTEMPTED;
1829
1830         vers = nfs4_ff_layout_ds_version(lseg, idx);
1831
1832         dprintk("%s ino %lu sync %d req %Zu@%llu DS: %s cl_count %d vers %d\n",
1833                 __func__, hdr->inode->i_ino, sync, (size_t) hdr->args.count,
1834                 offset, ds->ds_remotestr, atomic_read(&ds->ds_clp->cl_count),
1835                 vers);
1836
1837         hdr->pgio_done_cb = ff_layout_write_done_cb;
1838         atomic_inc(&ds->ds_clp->cl_count);
1839         hdr->ds_clp = ds->ds_clp;
1840         hdr->ds_commit_idx = idx;
1841         fh = nfs4_ff_layout_select_ds_fh(lseg, idx);
1842         if (fh)
1843                 hdr->args.fh = fh;
1844
1845         /*
1846          * Note that if we ever decide to split across DSes,
1847          * then we may need to handle dense-like offsets.
1848          */
1849         hdr->args.offset = offset;
1850
1851         /* Perform an asynchronous write */
1852         nfs_initiate_pgio(ds_clnt, hdr, ds_cred, ds->ds_clp->rpc_ops,
1853                           vers == 3 ? &ff_layout_write_call_ops_v3 :
1854                                       &ff_layout_write_call_ops_v4,
1855                           sync, RPC_TASK_SOFTCONN);
1856         put_rpccred(ds_cred);
1857         return PNFS_ATTEMPTED;
1858 }
1859
1860 static u32 calc_ds_index_from_commit(struct pnfs_layout_segment *lseg, u32 i)
1861 {
1862         return i;
1863 }
1864
1865 static struct nfs_fh *
1866 select_ds_fh_from_commit(struct pnfs_layout_segment *lseg, u32 i)
1867 {
1868         struct nfs4_ff_layout_segment *flseg = FF_LAYOUT_LSEG(lseg);
1869
1870         /* FIXME: Assume that there is only one NFS version available
1871          * for the DS.
1872          */
1873         return &flseg->mirror_array[i]->fh_versions[0];
1874 }
1875
1876 static int ff_layout_initiate_commit(struct nfs_commit_data *data, int how)
1877 {
1878         struct pnfs_layout_segment *lseg = data->lseg;
1879         struct nfs4_pnfs_ds *ds;
1880         struct rpc_clnt *ds_clnt;
1881         struct rpc_cred *ds_cred;
1882         u32 idx;
1883         int vers, ret;
1884         struct nfs_fh *fh;
1885
1886         idx = calc_ds_index_from_commit(lseg, data->ds_commit_index);
1887         ds = nfs4_ff_layout_prepare_ds(lseg, idx, true);
1888         if (!ds)
1889                 goto out_err;
1890
1891         ds_clnt = nfs4_ff_find_or_create_ds_client(lseg, idx, ds->ds_clp,
1892                                                    data->inode);
1893         if (IS_ERR(ds_clnt))
1894                 goto out_err;
1895
1896         ds_cred = ff_layout_get_ds_cred(lseg, idx, data->cred);
1897         if (!ds_cred)
1898                 goto out_err;
1899
1900         vers = nfs4_ff_layout_ds_version(lseg, idx);
1901
1902         dprintk("%s ino %lu, how %d cl_count %d vers %d\n", __func__,
1903                 data->inode->i_ino, how, atomic_read(&ds->ds_clp->cl_count),
1904                 vers);
1905         data->commit_done_cb = ff_layout_commit_done_cb;
1906         data->cred = ds_cred;
1907         atomic_inc(&ds->ds_clp->cl_count);
1908         data->ds_clp = ds->ds_clp;
1909         fh = select_ds_fh_from_commit(lseg, data->ds_commit_index);
1910         if (fh)
1911                 data->args.fh = fh;
1912
1913         ret = nfs_initiate_commit(ds_clnt, data, ds->ds_clp->rpc_ops,
1914                                    vers == 3 ? &ff_layout_commit_call_ops_v3 :
1915                                                &ff_layout_commit_call_ops_v4,
1916                                    how, RPC_TASK_SOFTCONN);
1917         put_rpccred(ds_cred);
1918         return ret;
1919 out_err:
1920         pnfs_generic_prepare_to_resend_writes(data);
1921         pnfs_generic_commit_release(data);
1922         return -EAGAIN;
1923 }
1924
1925 static int
1926 ff_layout_commit_pagelist(struct inode *inode, struct list_head *mds_pages,
1927                            int how, struct nfs_commit_info *cinfo)
1928 {
1929         return pnfs_generic_commit_pagelist(inode, mds_pages, how, cinfo,
1930                                             ff_layout_initiate_commit);
1931 }
1932
1933 static struct pnfs_ds_commit_info *
1934 ff_layout_get_ds_info(struct inode *inode)
1935 {
1936         struct pnfs_layout_hdr *layout = NFS_I(inode)->layout;
1937
1938         if (layout == NULL)
1939                 return NULL;
1940
1941         return &FF_LAYOUT_FROM_HDR(layout)->commit_info;
1942 }
1943
1944 static void
1945 ff_layout_free_deviceid_node(struct nfs4_deviceid_node *d)
1946 {
1947         nfs4_ff_layout_free_deviceid(container_of(d, struct nfs4_ff_layout_ds,
1948                                                   id_node));
1949 }
1950
1951 static int ff_layout_encode_ioerr(struct xdr_stream *xdr,
1952                                   const struct nfs4_layoutreturn_args *args,
1953                                   const struct nfs4_flexfile_layoutreturn_args *ff_args)
1954 {
1955         __be32 *start;
1956
1957         start = xdr_reserve_space(xdr, 4);
1958         if (unlikely(!start))
1959                 return -E2BIG;
1960
1961         *start = cpu_to_be32(ff_args->num_errors);
1962         /* This assume we always return _ALL_ layouts */
1963         return ff_layout_encode_ds_ioerr(xdr, &ff_args->errors);
1964 }
1965
1966 static void
1967 encode_opaque_fixed(struct xdr_stream *xdr, const void *buf, size_t len)
1968 {
1969         __be32 *p;
1970
1971         p = xdr_reserve_space(xdr, len);
1972         xdr_encode_opaque_fixed(p, buf, len);
1973 }
1974
1975 static void
1976 ff_layout_encode_ff_iostat_head(struct xdr_stream *xdr,
1977                             const nfs4_stateid *stateid,
1978                             const struct nfs42_layoutstat_devinfo *devinfo)
1979 {
1980         __be32 *p;
1981
1982         p = xdr_reserve_space(xdr, 8 + 8);
1983         p = xdr_encode_hyper(p, devinfo->offset);
1984         p = xdr_encode_hyper(p, devinfo->length);
1985         encode_opaque_fixed(xdr, stateid->data, NFS4_STATEID_SIZE);
1986         p = xdr_reserve_space(xdr, 4*8);
1987         p = xdr_encode_hyper(p, devinfo->read_count);
1988         p = xdr_encode_hyper(p, devinfo->read_bytes);
1989         p = xdr_encode_hyper(p, devinfo->write_count);
1990         p = xdr_encode_hyper(p, devinfo->write_bytes);
1991         encode_opaque_fixed(xdr, devinfo->dev_id.data, NFS4_DEVICEID4_SIZE);
1992 }
1993
1994 static void
1995 ff_layout_encode_ff_iostat(struct xdr_stream *xdr,
1996                             const nfs4_stateid *stateid,
1997                             const struct nfs42_layoutstat_devinfo *devinfo)
1998 {
1999         ff_layout_encode_ff_iostat_head(xdr, stateid, devinfo);
2000         ff_layout_encode_ff_layoutupdate(xdr, devinfo,
2001                         devinfo->ld_private.data);
2002 }
2003
2004 /* report nothing for now */
2005 static void ff_layout_encode_iostats_array(struct xdr_stream *xdr,
2006                 const struct nfs4_layoutreturn_args *args,
2007                 struct nfs4_flexfile_layoutreturn_args *ff_args)
2008 {
2009         __be32 *p;
2010         int i;
2011
2012         p = xdr_reserve_space(xdr, 4);
2013         *p = cpu_to_be32(ff_args->num_dev);
2014         for (i = 0; i < ff_args->num_dev; i++)
2015                 ff_layout_encode_ff_iostat(xdr,
2016                                 &args->layout->plh_stateid,
2017                                 &ff_args->devinfo[i]);
2018 }
2019
2020 static void
2021 ff_layout_free_iostats_array(struct nfs42_layoutstat_devinfo *devinfo,
2022                 unsigned int num_entries)
2023 {
2024         unsigned int i;
2025
2026         for (i = 0; i < num_entries; i++) {
2027                 if (!devinfo[i].ld_private.ops)
2028                         continue;
2029                 if (!devinfo[i].ld_private.ops->free)
2030                         continue;
2031                 devinfo[i].ld_private.ops->free(&devinfo[i].ld_private);
2032         }
2033 }
2034
2035 static struct nfs4_deviceid_node *
2036 ff_layout_alloc_deviceid_node(struct nfs_server *server,
2037                               struct pnfs_device *pdev, gfp_t gfp_flags)
2038 {
2039         struct nfs4_ff_layout_ds *dsaddr;
2040
2041         dsaddr = nfs4_ff_alloc_deviceid_node(server, pdev, gfp_flags);
2042         if (!dsaddr)
2043                 return NULL;
2044         return &dsaddr->id_node;
2045 }
2046
2047 static void
2048 ff_layout_encode_layoutreturn(struct xdr_stream *xdr,
2049                 const void *voidargs,
2050                 const struct nfs4_xdr_opaque_data *ff_opaque)
2051 {
2052         const struct nfs4_layoutreturn_args *args = voidargs;
2053         struct nfs4_flexfile_layoutreturn_args *ff_args = ff_opaque->data;
2054         struct xdr_buf tmp_buf = {
2055                 .head = {
2056                         [0] = {
2057                                 .iov_base = page_address(ff_args->pages[0]),
2058                         },
2059                 },
2060                 .buflen = PAGE_SIZE,
2061         };
2062         struct xdr_stream tmp_xdr;
2063         __be32 *start;
2064
2065         dprintk("%s: Begin\n", __func__);
2066
2067         xdr_init_encode(&tmp_xdr, &tmp_buf, NULL);
2068
2069         ff_layout_encode_ioerr(&tmp_xdr, args, ff_args);
2070         ff_layout_encode_iostats_array(&tmp_xdr, args, ff_args);
2071
2072         start = xdr_reserve_space(xdr, 4);
2073         *start = cpu_to_be32(tmp_buf.len);
2074         xdr_write_pages(xdr, ff_args->pages, 0, tmp_buf.len);
2075
2076         dprintk("%s: Return\n", __func__);
2077 }
2078
2079 static void
2080 ff_layout_free_layoutreturn(struct nfs4_xdr_opaque_data *args)
2081 {
2082         struct nfs4_flexfile_layoutreturn_args *ff_args;
2083
2084         if (!args->data)
2085                 return;
2086         ff_args = args->data;
2087         args->data = NULL;
2088
2089         ff_layout_free_ds_ioerr(&ff_args->errors);
2090         ff_layout_free_iostats_array(ff_args->devinfo, ff_args->num_dev);
2091
2092         put_page(ff_args->pages[0]);
2093         kfree(ff_args);
2094 }
2095
2096 const struct nfs4_xdr_opaque_ops layoutreturn_ops = {
2097         .encode = ff_layout_encode_layoutreturn,
2098         .free = ff_layout_free_layoutreturn,
2099 };
2100
2101 static int
2102 ff_layout_prepare_layoutreturn(struct nfs4_layoutreturn_args *args)
2103 {
2104         struct nfs4_flexfile_layoutreturn_args *ff_args;
2105         struct nfs4_flexfile_layout *ff_layout = FF_LAYOUT_FROM_HDR(args->layout);
2106
2107         ff_args = kmalloc(sizeof(*ff_args), GFP_KERNEL);
2108         if (!ff_args)
2109                 goto out_nomem;
2110         ff_args->pages[0] = alloc_page(GFP_KERNEL);
2111         if (!ff_args->pages[0])
2112                 goto out_nomem_free;
2113
2114         INIT_LIST_HEAD(&ff_args->errors);
2115         ff_args->num_errors = ff_layout_fetch_ds_ioerr(args->layout,
2116                         &args->range, &ff_args->errors,
2117                         FF_LAYOUTRETURN_MAXERR);
2118
2119         spin_lock(&args->inode->i_lock);
2120         ff_args->num_dev = ff_layout_mirror_prepare_stats(&ff_layout->generic_hdr,
2121                         &ff_args->devinfo[0], ARRAY_SIZE(ff_args->devinfo));
2122         spin_unlock(&args->inode->i_lock);
2123
2124         args->ld_private->ops = &layoutreturn_ops;
2125         args->ld_private->data = ff_args;
2126         return 0;
2127 out_nomem_free:
2128         kfree(ff_args);
2129 out_nomem:
2130         return -ENOMEM;
2131 }
2132
2133 static int
2134 ff_layout_ntop4(const struct sockaddr *sap, char *buf, const size_t buflen)
2135 {
2136         const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
2137
2138         return snprintf(buf, buflen, "%pI4", &sin->sin_addr);
2139 }
2140
2141 static size_t
2142 ff_layout_ntop6_noscopeid(const struct sockaddr *sap, char *buf,
2143                           const int buflen)
2144 {
2145         const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
2146         const struct in6_addr *addr = &sin6->sin6_addr;
2147
2148         /*
2149          * RFC 4291, Section 2.2.2
2150          *
2151          * Shorthanded ANY address
2152          */
2153         if (ipv6_addr_any(addr))
2154                 return snprintf(buf, buflen, "::");
2155
2156         /*
2157          * RFC 4291, Section 2.2.2
2158          *
2159          * Shorthanded loopback address
2160          */
2161         if (ipv6_addr_loopback(addr))
2162                 return snprintf(buf, buflen, "::1");
2163
2164         /*
2165          * RFC 4291, Section 2.2.3
2166          *
2167          * Special presentation address format for mapped v4
2168          * addresses.
2169          */
2170         if (ipv6_addr_v4mapped(addr))
2171                 return snprintf(buf, buflen, "::ffff:%pI4",
2172                                         &addr->s6_addr32[3]);
2173
2174         /*
2175          * RFC 4291, Section 2.2.1
2176          */
2177         return snprintf(buf, buflen, "%pI6c", addr);
2178 }
2179
2180 /* Derived from rpc_sockaddr2uaddr */
2181 static void
2182 ff_layout_encode_netaddr(struct xdr_stream *xdr, struct nfs4_pnfs_ds_addr *da)
2183 {
2184         struct sockaddr *sap = (struct sockaddr *)&da->da_addr;
2185         char portbuf[RPCBIND_MAXUADDRPLEN];
2186         char addrbuf[RPCBIND_MAXUADDRLEN];
2187         char *netid;
2188         unsigned short port;
2189         int len, netid_len;
2190         __be32 *p;
2191
2192         switch (sap->sa_family) {
2193         case AF_INET:
2194                 if (ff_layout_ntop4(sap, addrbuf, sizeof(addrbuf)) == 0)
2195                         return;
2196                 port = ntohs(((struct sockaddr_in *)sap)->sin_port);
2197                 netid = "tcp";
2198                 netid_len = 3;
2199                 break;
2200         case AF_INET6:
2201                 if (ff_layout_ntop6_noscopeid(sap, addrbuf, sizeof(addrbuf)) == 0)
2202                         return;
2203                 port = ntohs(((struct sockaddr_in6 *)sap)->sin6_port);
2204                 netid = "tcp6";
2205                 netid_len = 4;
2206                 break;
2207         default:
2208                 /* we only support tcp and tcp6 */
2209                 WARN_ON_ONCE(1);
2210                 return;
2211         }
2212
2213         snprintf(portbuf, sizeof(portbuf), ".%u.%u", port >> 8, port & 0xff);
2214         len = strlcat(addrbuf, portbuf, sizeof(addrbuf));
2215
2216         p = xdr_reserve_space(xdr, 4 + netid_len);
2217         xdr_encode_opaque(p, netid, netid_len);
2218
2219         p = xdr_reserve_space(xdr, 4 + len);
2220         xdr_encode_opaque(p, addrbuf, len);
2221 }
2222
2223 static void
2224 ff_layout_encode_nfstime(struct xdr_stream *xdr,
2225                          ktime_t t)
2226 {
2227         struct timespec64 ts;
2228         __be32 *p;
2229
2230         p = xdr_reserve_space(xdr, 12);
2231         ts = ktime_to_timespec64(t);
2232         p = xdr_encode_hyper(p, ts.tv_sec);
2233         *p++ = cpu_to_be32(ts.tv_nsec);
2234 }
2235
2236 static void
2237 ff_layout_encode_io_latency(struct xdr_stream *xdr,
2238                             struct nfs4_ff_io_stat *stat)
2239 {
2240         __be32 *p;
2241
2242         p = xdr_reserve_space(xdr, 5 * 8);
2243         p = xdr_encode_hyper(p, stat->ops_requested);
2244         p = xdr_encode_hyper(p, stat->bytes_requested);
2245         p = xdr_encode_hyper(p, stat->ops_completed);
2246         p = xdr_encode_hyper(p, stat->bytes_completed);
2247         p = xdr_encode_hyper(p, stat->bytes_not_delivered);
2248         ff_layout_encode_nfstime(xdr, stat->total_busy_time);
2249         ff_layout_encode_nfstime(xdr, stat->aggregate_completion_time);
2250 }
2251
2252 static void
2253 ff_layout_encode_ff_layoutupdate(struct xdr_stream *xdr,
2254                               const struct nfs42_layoutstat_devinfo *devinfo,
2255                               struct nfs4_ff_layout_mirror *mirror)
2256 {
2257         struct nfs4_pnfs_ds_addr *da;
2258         struct nfs4_pnfs_ds *ds = mirror->mirror_ds->ds;
2259         struct nfs_fh *fh = &mirror->fh_versions[0];
2260         __be32 *p;
2261
2262         da = list_first_entry(&ds->ds_addrs, struct nfs4_pnfs_ds_addr, da_node);
2263         dprintk("%s: DS %s: encoding address %s\n",
2264                 __func__, ds->ds_remotestr, da->da_remotestr);
2265         /* netaddr4 */
2266         ff_layout_encode_netaddr(xdr, da);
2267         /* nfs_fh4 */
2268         p = xdr_reserve_space(xdr, 4 + fh->size);
2269         xdr_encode_opaque(p, fh->data, fh->size);
2270         /* ff_io_latency4 read */
2271         spin_lock(&mirror->lock);
2272         ff_layout_encode_io_latency(xdr, &mirror->read_stat.io_stat);
2273         /* ff_io_latency4 write */
2274         ff_layout_encode_io_latency(xdr, &mirror->write_stat.io_stat);
2275         spin_unlock(&mirror->lock);
2276         /* nfstime4 */
2277         ff_layout_encode_nfstime(xdr, ktime_sub(ktime_get(), mirror->start_time));
2278         /* bool */
2279         p = xdr_reserve_space(xdr, 4);
2280         *p = cpu_to_be32(false);
2281 }
2282
2283 static void
2284 ff_layout_encode_layoutstats(struct xdr_stream *xdr, const void *args,
2285                              const struct nfs4_xdr_opaque_data *opaque)
2286 {
2287         struct nfs42_layoutstat_devinfo *devinfo = container_of(opaque,
2288                         struct nfs42_layoutstat_devinfo, ld_private);
2289         __be32 *start;
2290
2291         /* layoutupdate length */
2292         start = xdr_reserve_space(xdr, 4);
2293         ff_layout_encode_ff_layoutupdate(xdr, devinfo, opaque->data);
2294
2295         *start = cpu_to_be32((xdr->p - start - 1) * 4);
2296 }
2297
2298 static void
2299 ff_layout_free_layoutstats(struct nfs4_xdr_opaque_data *opaque)
2300 {
2301         struct nfs4_ff_layout_mirror *mirror = opaque->data;
2302
2303         ff_layout_put_mirror(mirror);
2304 }
2305
2306 static const struct nfs4_xdr_opaque_ops layoutstat_ops = {
2307         .encode = ff_layout_encode_layoutstats,
2308         .free   = ff_layout_free_layoutstats,
2309 };
2310
2311 static int
2312 ff_layout_mirror_prepare_stats(struct pnfs_layout_hdr *lo,
2313                                struct nfs42_layoutstat_devinfo *devinfo,
2314                                int dev_limit)
2315 {
2316         struct nfs4_flexfile_layout *ff_layout = FF_LAYOUT_FROM_HDR(lo);
2317         struct nfs4_ff_layout_mirror *mirror;
2318         struct nfs4_deviceid_node *dev;
2319         int i = 0;
2320
2321         list_for_each_entry(mirror, &ff_layout->mirrors, mirrors) {
2322                 if (i >= dev_limit)
2323                         break;
2324                 if (IS_ERR_OR_NULL(mirror->mirror_ds))
2325                         continue;
2326                 if (!test_and_clear_bit(NFS4_FF_MIRROR_STAT_AVAIL, &mirror->flags))
2327                         continue;
2328                 /* mirror refcount put in cleanup_layoutstats */
2329                 if (!atomic_inc_not_zero(&mirror->ref))
2330                         continue;
2331                 dev = &mirror->mirror_ds->id_node;
2332                 memcpy(&devinfo->dev_id, &dev->deviceid, NFS4_DEVICEID4_SIZE);
2333                 devinfo->offset = 0;
2334                 devinfo->length = NFS4_MAX_UINT64;
2335                 spin_lock(&mirror->lock);
2336                 devinfo->read_count = mirror->read_stat.io_stat.ops_completed;
2337                 devinfo->read_bytes = mirror->read_stat.io_stat.bytes_completed;
2338                 devinfo->write_count = mirror->write_stat.io_stat.ops_completed;
2339                 devinfo->write_bytes = mirror->write_stat.io_stat.bytes_completed;
2340                 spin_unlock(&mirror->lock);
2341                 devinfo->layout_type = LAYOUT_FLEX_FILES;
2342                 devinfo->ld_private.ops = &layoutstat_ops;
2343                 devinfo->ld_private.data = mirror;
2344
2345                 devinfo++;
2346                 i++;
2347         }
2348         return i;
2349 }
2350
2351 static int
2352 ff_layout_prepare_layoutstats(struct nfs42_layoutstat_args *args)
2353 {
2354         struct nfs4_flexfile_layout *ff_layout;
2355         const int dev_count = PNFS_LAYOUTSTATS_MAXDEV;
2356
2357         /* For now, send at most PNFS_LAYOUTSTATS_MAXDEV statistics */
2358         args->devinfo = kmalloc_array(dev_count, sizeof(*args->devinfo), GFP_NOIO);
2359         if (!args->devinfo)
2360                 return -ENOMEM;
2361
2362         spin_lock(&args->inode->i_lock);
2363         ff_layout = FF_LAYOUT_FROM_HDR(NFS_I(args->inode)->layout);
2364         args->num_dev = ff_layout_mirror_prepare_stats(&ff_layout->generic_hdr,
2365                         &args->devinfo[0], dev_count);
2366         spin_unlock(&args->inode->i_lock);
2367         if (!args->num_dev) {
2368                 kfree(args->devinfo);
2369                 args->devinfo = NULL;
2370                 return -ENOENT;
2371         }
2372
2373         return 0;
2374 }
2375
2376 static struct pnfs_layoutdriver_type flexfilelayout_type = {
2377         .id                     = LAYOUT_FLEX_FILES,
2378         .name                   = "LAYOUT_FLEX_FILES",
2379         .owner                  = THIS_MODULE,
2380         .alloc_layout_hdr       = ff_layout_alloc_layout_hdr,
2381         .free_layout_hdr        = ff_layout_free_layout_hdr,
2382         .alloc_lseg             = ff_layout_alloc_lseg,
2383         .free_lseg              = ff_layout_free_lseg,
2384         .add_lseg               = ff_layout_add_lseg,
2385         .pg_read_ops            = &ff_layout_pg_read_ops,
2386         .pg_write_ops           = &ff_layout_pg_write_ops,
2387         .get_ds_info            = ff_layout_get_ds_info,
2388         .free_deviceid_node     = ff_layout_free_deviceid_node,
2389         .mark_request_commit    = pnfs_layout_mark_request_commit,
2390         .clear_request_commit   = pnfs_generic_clear_request_commit,
2391         .scan_commit_lists      = pnfs_generic_scan_commit_lists,
2392         .recover_commit_reqs    = pnfs_generic_recover_commit_reqs,
2393         .commit_pagelist        = ff_layout_commit_pagelist,
2394         .read_pagelist          = ff_layout_read_pagelist,
2395         .write_pagelist         = ff_layout_write_pagelist,
2396         .alloc_deviceid_node    = ff_layout_alloc_deviceid_node,
2397         .prepare_layoutreturn   = ff_layout_prepare_layoutreturn,
2398         .sync                   = pnfs_nfs_generic_sync,
2399         .prepare_layoutstats    = ff_layout_prepare_layoutstats,
2400 };
2401
2402 static int __init nfs4flexfilelayout_init(void)
2403 {
2404         printk(KERN_INFO "%s: NFSv4 Flexfile Layout Driver Registering...\n",
2405                __func__);
2406         if (!ff_zero_group) {
2407                 ff_zero_group = groups_alloc(0);
2408                 if (!ff_zero_group)
2409                         return -ENOMEM;
2410         }
2411         return pnfs_register_layoutdriver(&flexfilelayout_type);
2412 }
2413
2414 static void __exit nfs4flexfilelayout_exit(void)
2415 {
2416         printk(KERN_INFO "%s: NFSv4 Flexfile Layout Driver Unregistering...\n",
2417                __func__);
2418         pnfs_unregister_layoutdriver(&flexfilelayout_type);
2419         if (ff_zero_group) {
2420                 put_group_info(ff_zero_group);
2421                 ff_zero_group = NULL;
2422         }
2423 }
2424
2425 MODULE_ALIAS("nfs-layouttype4-4");
2426
2427 MODULE_LICENSE("GPL");
2428 MODULE_DESCRIPTION("The NFSv4 flexfile layout driver");
2429
2430 module_init(nfs4flexfilelayout_init);
2431 module_exit(nfs4flexfilelayout_exit);