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_mark_deviceid_unavailable(devid);
1130                 rpc_wake_up(&tbl->slot_tbl_waitq);
1131                 /* fall through */
1132         default:
1133                 if (ff_layout_avoid_mds_available_ds(lseg))
1134                         return -NFS4ERR_RESET_TO_PNFS;
1135 reset:
1136                 dprintk("%s Retry through MDS. Error %d\n", __func__,
1137                         task->tk_status);
1138                 return -NFS4ERR_RESET_TO_MDS;
1139         }
1140 out:
1141         task->tk_status = 0;
1142         return -EAGAIN;
1143 out_bad_stateid:
1144         task->tk_status = -EIO;
1145         return 0;
1146 wait_on_recovery:
1147         rpc_sleep_on(&mds_client->cl_rpcwaitq, task, NULL);
1148         if (test_bit(NFS4CLNT_MANAGER_RUNNING, &mds_client->cl_state) == 0)
1149                 rpc_wake_up_queued_task(&mds_client->cl_rpcwaitq, task);
1150         goto out;
1151 }
1152
1153 /* Retry all errors through either pNFS or MDS except for -EJUKEBOX */
1154 static int ff_layout_async_handle_error_v3(struct rpc_task *task,
1155                                            struct pnfs_layout_segment *lseg,
1156                                            int idx)
1157 {
1158         struct nfs4_deviceid_node *devid = FF_LAYOUT_DEVID_NODE(lseg, idx);
1159
1160         if (task->tk_status >= 0)
1161                 return 0;
1162
1163         switch (task->tk_status) {
1164         /* File access problems. Don't mark the device as unavailable */
1165         case -EACCES:
1166         case -ESTALE:
1167         case -EISDIR:
1168         case -EBADHANDLE:
1169         case -ELOOP:
1170         case -ENOSPC:
1171                 break;
1172         case -EJUKEBOX:
1173                 nfs_inc_stats(lseg->pls_layout->plh_inode, NFSIOS_DELAY);
1174                 goto out_retry;
1175         default:
1176                 dprintk("%s DS connection error %d\n", __func__,
1177                         task->tk_status);
1178                 nfs4_mark_deviceid_unavailable(devid);
1179         }
1180         /* FIXME: Need to prevent infinite looping here. */
1181         return -NFS4ERR_RESET_TO_PNFS;
1182 out_retry:
1183         task->tk_status = 0;
1184         rpc_restart_call_prepare(task);
1185         rpc_delay(task, NFS_JUKEBOX_RETRY_TIME);
1186         return -EAGAIN;
1187 }
1188
1189 static int ff_layout_async_handle_error(struct rpc_task *task,
1190                                         struct nfs4_state *state,
1191                                         struct nfs_client *clp,
1192                                         struct pnfs_layout_segment *lseg,
1193                                         int idx)
1194 {
1195         int vers = clp->cl_nfs_mod->rpc_vers->number;
1196
1197         switch (vers) {
1198         case 3:
1199                 return ff_layout_async_handle_error_v3(task, lseg, idx);
1200         case 4:
1201                 return ff_layout_async_handle_error_v4(task, state, clp,
1202                                                        lseg, idx);
1203         default:
1204                 /* should never happen */
1205                 WARN_ON_ONCE(1);
1206                 return 0;
1207         }
1208 }
1209
1210 static void ff_layout_io_track_ds_error(struct pnfs_layout_segment *lseg,
1211                                         int idx, u64 offset, u64 length,
1212                                         u32 status, int opnum, int error)
1213 {
1214         struct nfs4_ff_layout_mirror *mirror;
1215         int err;
1216
1217         if (status == 0) {
1218                 switch (error) {
1219                 case -ETIMEDOUT:
1220                 case -EPFNOSUPPORT:
1221                 case -EPROTONOSUPPORT:
1222                 case -EOPNOTSUPP:
1223                 case -ECONNREFUSED:
1224                 case -ECONNRESET:
1225                 case -EHOSTDOWN:
1226                 case -EHOSTUNREACH:
1227                 case -ENETUNREACH:
1228                 case -EADDRINUSE:
1229                 case -ENOBUFS:
1230                 case -EPIPE:
1231                 case -EPERM:
1232                         status = NFS4ERR_NXIO;
1233                         break;
1234                 case -EACCES:
1235                         status = NFS4ERR_ACCESS;
1236                         break;
1237                 default:
1238                         return;
1239                 }
1240         }
1241
1242         switch (status) {
1243         case NFS4ERR_DELAY:
1244         case NFS4ERR_GRACE:
1245                 return;
1246         default:
1247                 break;
1248         }
1249
1250         mirror = FF_LAYOUT_COMP(lseg, idx);
1251         err = ff_layout_track_ds_error(FF_LAYOUT_FROM_HDR(lseg->pls_layout),
1252                                        mirror, offset, length, status, opnum,
1253                                        GFP_NOIO);
1254         pnfs_error_mark_layout_for_return(lseg->pls_layout->plh_inode, lseg);
1255         dprintk("%s: err %d op %d status %u\n", __func__, err, opnum, status);
1256 }
1257
1258 /* NFS_PROTO call done callback routines */
1259 static int ff_layout_read_done_cb(struct rpc_task *task,
1260                                 struct nfs_pgio_header *hdr)
1261 {
1262         int err;
1263
1264         trace_nfs4_pnfs_read(hdr, task->tk_status);
1265         if (task->tk_status < 0)
1266                 ff_layout_io_track_ds_error(hdr->lseg, hdr->pgio_mirror_idx,
1267                                             hdr->args.offset, hdr->args.count,
1268                                             hdr->res.op_status, OP_READ,
1269                                             task->tk_status);
1270         err = ff_layout_async_handle_error(task, hdr->args.context->state,
1271                                            hdr->ds_clp, hdr->lseg,
1272                                            hdr->pgio_mirror_idx);
1273
1274         switch (err) {
1275         case -NFS4ERR_RESET_TO_PNFS:
1276                 if (ff_layout_choose_best_ds_for_read(hdr->lseg,
1277                                         hdr->pgio_mirror_idx + 1,
1278                                         &hdr->pgio_mirror_idx))
1279                         goto out_eagain;
1280                 ff_layout_read_record_layoutstats_done(task, hdr);
1281                 pnfs_read_resend_pnfs(hdr);
1282                 return task->tk_status;
1283         case -NFS4ERR_RESET_TO_MDS:
1284                 ff_layout_reset_read(hdr);
1285                 return task->tk_status;
1286         case -EAGAIN:
1287                 goto out_eagain;
1288         }
1289
1290         return 0;
1291 out_eagain:
1292         rpc_restart_call_prepare(task);
1293         return -EAGAIN;
1294 }
1295
1296 static bool
1297 ff_layout_need_layoutcommit(struct pnfs_layout_segment *lseg)
1298 {
1299         return !(FF_LAYOUT_LSEG(lseg)->flags & FF_FLAGS_NO_LAYOUTCOMMIT);
1300 }
1301
1302 /*
1303  * We reference the rpc_cred of the first WRITE that triggers the need for
1304  * a LAYOUTCOMMIT, and use it to send the layoutcommit compound.
1305  * rfc5661 is not clear about which credential should be used.
1306  *
1307  * Flexlayout client should treat DS replied FILE_SYNC as DATA_SYNC, so
1308  * to follow http://www.rfc-editor.org/errata_search.php?rfc=5661&eid=2751
1309  * we always send layoutcommit after DS writes.
1310  */
1311 static void
1312 ff_layout_set_layoutcommit(struct inode *inode,
1313                 struct pnfs_layout_segment *lseg,
1314                 loff_t end_offset)
1315 {
1316         if (!ff_layout_need_layoutcommit(lseg))
1317                 return;
1318
1319         pnfs_set_layoutcommit(inode, lseg, end_offset);
1320         dprintk("%s inode %lu pls_end_pos %llu\n", __func__, inode->i_ino,
1321                 (unsigned long long) NFS_I(inode)->layout->plh_lwb);
1322 }
1323
1324 static bool
1325 ff_layout_device_unavailable(struct pnfs_layout_segment *lseg, int idx)
1326 {
1327         /* No mirroring for now */
1328         struct nfs4_deviceid_node *node = FF_LAYOUT_DEVID_NODE(lseg, idx);
1329
1330         return ff_layout_test_devid_unavailable(node);
1331 }
1332
1333 static void ff_layout_read_record_layoutstats_start(struct rpc_task *task,
1334                 struct nfs_pgio_header *hdr)
1335 {
1336         if (test_and_set_bit(NFS_IOHDR_STAT, &hdr->flags))
1337                 return;
1338         nfs4_ff_layout_stat_io_start_read(hdr->inode,
1339                         FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
1340                         hdr->args.count,
1341                         task->tk_start);
1342 }
1343
1344 static void ff_layout_read_record_layoutstats_done(struct rpc_task *task,
1345                 struct nfs_pgio_header *hdr)
1346 {
1347         if (!test_and_clear_bit(NFS_IOHDR_STAT, &hdr->flags))
1348                 return;
1349         nfs4_ff_layout_stat_io_end_read(task,
1350                         FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
1351                         hdr->args.count,
1352                         hdr->res.count);
1353 }
1354
1355 static int ff_layout_read_prepare_common(struct rpc_task *task,
1356                                          struct nfs_pgio_header *hdr)
1357 {
1358         if (unlikely(test_bit(NFS_CONTEXT_BAD, &hdr->args.context->flags))) {
1359                 rpc_exit(task, -EIO);
1360                 return -EIO;
1361         }
1362         if (ff_layout_device_unavailable(hdr->lseg, hdr->pgio_mirror_idx)) {
1363                 rpc_exit(task, -EHOSTDOWN);
1364                 return -EAGAIN;
1365         }
1366
1367         ff_layout_read_record_layoutstats_start(task, hdr);
1368         return 0;
1369 }
1370
1371 /*
1372  * Call ops for the async read/write cases
1373  * In the case of dense layouts, the offset needs to be reset to its
1374  * original value.
1375  */
1376 static void ff_layout_read_prepare_v3(struct rpc_task *task, void *data)
1377 {
1378         struct nfs_pgio_header *hdr = data;
1379
1380         if (ff_layout_read_prepare_common(task, hdr))
1381                 return;
1382
1383         rpc_call_start(task);
1384 }
1385
1386 static int ff_layout_setup_sequence(struct nfs_client *ds_clp,
1387                                     struct nfs4_sequence_args *args,
1388                                     struct nfs4_sequence_res *res,
1389                                     struct rpc_task *task)
1390 {
1391         if (ds_clp->cl_session)
1392                 return nfs41_setup_sequence(ds_clp->cl_session,
1393                                            args,
1394                                            res,
1395                                            task);
1396         return nfs40_setup_sequence(ds_clp->cl_slot_tbl,
1397                                    args,
1398                                    res,
1399                                    task);
1400 }
1401
1402 static void ff_layout_read_prepare_v4(struct rpc_task *task, void *data)
1403 {
1404         struct nfs_pgio_header *hdr = data;
1405
1406         if (ff_layout_setup_sequence(hdr->ds_clp,
1407                                      &hdr->args.seq_args,
1408                                      &hdr->res.seq_res,
1409                                      task))
1410                 return;
1411
1412         if (ff_layout_read_prepare_common(task, hdr))
1413                 return;
1414
1415         if (nfs4_set_rw_stateid(&hdr->args.stateid, hdr->args.context,
1416                         hdr->args.lock_context, FMODE_READ) == -EIO)
1417                 rpc_exit(task, -EIO); /* lost lock, terminate I/O */
1418 }
1419
1420 static void ff_layout_read_call_done(struct rpc_task *task, void *data)
1421 {
1422         struct nfs_pgio_header *hdr = data;
1423
1424         dprintk("--> %s task->tk_status %d\n", __func__, task->tk_status);
1425
1426         if (test_bit(NFS_IOHDR_REDO, &hdr->flags) &&
1427             task->tk_status == 0) {
1428                 nfs4_sequence_done(task, &hdr->res.seq_res);
1429                 return;
1430         }
1431
1432         /* Note this may cause RPC to be resent */
1433         hdr->mds_ops->rpc_call_done(task, hdr);
1434 }
1435
1436 static void ff_layout_read_count_stats(struct rpc_task *task, void *data)
1437 {
1438         struct nfs_pgio_header *hdr = data;
1439
1440         ff_layout_read_record_layoutstats_done(task, hdr);
1441         rpc_count_iostats_metrics(task,
1442             &NFS_CLIENT(hdr->inode)->cl_metrics[NFSPROC4_CLNT_READ]);
1443 }
1444
1445 static void ff_layout_read_release(void *data)
1446 {
1447         struct nfs_pgio_header *hdr = data;
1448
1449         ff_layout_read_record_layoutstats_done(&hdr->task, hdr);
1450         pnfs_generic_rw_release(data);
1451 }
1452
1453
1454 static int ff_layout_write_done_cb(struct rpc_task *task,
1455                                 struct nfs_pgio_header *hdr)
1456 {
1457         loff_t end_offs = 0;
1458         int err;
1459
1460         trace_nfs4_pnfs_write(hdr, task->tk_status);
1461         if (task->tk_status < 0)
1462                 ff_layout_io_track_ds_error(hdr->lseg, hdr->pgio_mirror_idx,
1463                                             hdr->args.offset, hdr->args.count,
1464                                             hdr->res.op_status, OP_WRITE,
1465                                             task->tk_status);
1466         err = ff_layout_async_handle_error(task, hdr->args.context->state,
1467                                            hdr->ds_clp, hdr->lseg,
1468                                            hdr->pgio_mirror_idx);
1469
1470         switch (err) {
1471         case -NFS4ERR_RESET_TO_PNFS:
1472                 ff_layout_reset_write(hdr, true);
1473                 return task->tk_status;
1474         case -NFS4ERR_RESET_TO_MDS:
1475                 ff_layout_reset_write(hdr, false);
1476                 return task->tk_status;
1477         case -EAGAIN:
1478                 return -EAGAIN;
1479         }
1480
1481         if (hdr->res.verf->committed == NFS_FILE_SYNC ||
1482             hdr->res.verf->committed == NFS_DATA_SYNC)
1483                 end_offs = hdr->mds_offset + (loff_t)hdr->res.count;
1484
1485         /* Note: if the write is unstable, don't set end_offs until commit */
1486         ff_layout_set_layoutcommit(hdr->inode, hdr->lseg, end_offs);
1487
1488         /* zero out fattr since we don't care DS attr at all */
1489         hdr->fattr.valid = 0;
1490         if (task->tk_status >= 0)
1491                 nfs_writeback_update_inode(hdr);
1492
1493         return 0;
1494 }
1495
1496 static int ff_layout_commit_done_cb(struct rpc_task *task,
1497                                      struct nfs_commit_data *data)
1498 {
1499         int err;
1500
1501         trace_nfs4_pnfs_commit_ds(data, task->tk_status);
1502         if (task->tk_status < 0)
1503                 ff_layout_io_track_ds_error(data->lseg, data->ds_commit_index,
1504                                             data->args.offset, data->args.count,
1505                                             data->res.op_status, OP_COMMIT,
1506                                             task->tk_status);
1507         err = ff_layout_async_handle_error(task, NULL, data->ds_clp,
1508                                            data->lseg, data->ds_commit_index);
1509
1510         switch (err) {
1511         case -NFS4ERR_RESET_TO_PNFS:
1512                 pnfs_generic_prepare_to_resend_writes(data);
1513                 return -EAGAIN;
1514         case -NFS4ERR_RESET_TO_MDS:
1515                 pnfs_generic_prepare_to_resend_writes(data);
1516                 return -EAGAIN;
1517         case -EAGAIN:
1518                 rpc_restart_call_prepare(task);
1519                 return -EAGAIN;
1520         }
1521
1522         ff_layout_set_layoutcommit(data->inode, data->lseg, data->lwb);
1523
1524         return 0;
1525 }
1526
1527 static void ff_layout_write_record_layoutstats_start(struct rpc_task *task,
1528                 struct nfs_pgio_header *hdr)
1529 {
1530         if (test_and_set_bit(NFS_IOHDR_STAT, &hdr->flags))
1531                 return;
1532         nfs4_ff_layout_stat_io_start_write(hdr->inode,
1533                         FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
1534                         hdr->args.count,
1535                         task->tk_start);
1536 }
1537
1538 static void ff_layout_write_record_layoutstats_done(struct rpc_task *task,
1539                 struct nfs_pgio_header *hdr)
1540 {
1541         if (!test_and_clear_bit(NFS_IOHDR_STAT, &hdr->flags))
1542                 return;
1543         nfs4_ff_layout_stat_io_end_write(task,
1544                         FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
1545                         hdr->args.count, hdr->res.count,
1546                         hdr->res.verf->committed);
1547 }
1548
1549 static int ff_layout_write_prepare_common(struct rpc_task *task,
1550                                           struct nfs_pgio_header *hdr)
1551 {
1552         if (unlikely(test_bit(NFS_CONTEXT_BAD, &hdr->args.context->flags))) {
1553                 rpc_exit(task, -EIO);
1554                 return -EIO;
1555         }
1556
1557         if (ff_layout_device_unavailable(hdr->lseg, hdr->pgio_mirror_idx)) {
1558                 rpc_exit(task, -EHOSTDOWN);
1559                 return -EAGAIN;
1560         }
1561
1562         ff_layout_write_record_layoutstats_start(task, hdr);
1563         return 0;
1564 }
1565
1566 static void ff_layout_write_prepare_v3(struct rpc_task *task, void *data)
1567 {
1568         struct nfs_pgio_header *hdr = data;
1569
1570         if (ff_layout_write_prepare_common(task, hdr))
1571                 return;
1572
1573         rpc_call_start(task);
1574 }
1575
1576 static void ff_layout_write_prepare_v4(struct rpc_task *task, void *data)
1577 {
1578         struct nfs_pgio_header *hdr = data;
1579
1580         if (ff_layout_setup_sequence(hdr->ds_clp,
1581                                      &hdr->args.seq_args,
1582                                      &hdr->res.seq_res,
1583                                      task))
1584                 return;
1585
1586         if (ff_layout_write_prepare_common(task, hdr))
1587                 return;
1588
1589         if (nfs4_set_rw_stateid(&hdr->args.stateid, hdr->args.context,
1590                         hdr->args.lock_context, FMODE_WRITE) == -EIO)
1591                 rpc_exit(task, -EIO); /* lost lock, terminate I/O */
1592 }
1593
1594 static void ff_layout_write_call_done(struct rpc_task *task, void *data)
1595 {
1596         struct nfs_pgio_header *hdr = data;
1597
1598         if (test_bit(NFS_IOHDR_REDO, &hdr->flags) &&
1599             task->tk_status == 0) {
1600                 nfs4_sequence_done(task, &hdr->res.seq_res);
1601                 return;
1602         }
1603
1604         /* Note this may cause RPC to be resent */
1605         hdr->mds_ops->rpc_call_done(task, hdr);
1606 }
1607
1608 static void ff_layout_write_count_stats(struct rpc_task *task, void *data)
1609 {
1610         struct nfs_pgio_header *hdr = data;
1611
1612         ff_layout_write_record_layoutstats_done(task, hdr);
1613         rpc_count_iostats_metrics(task,
1614             &NFS_CLIENT(hdr->inode)->cl_metrics[NFSPROC4_CLNT_WRITE]);
1615 }
1616
1617 static void ff_layout_write_release(void *data)
1618 {
1619         struct nfs_pgio_header *hdr = data;
1620
1621         ff_layout_write_record_layoutstats_done(&hdr->task, hdr);
1622         pnfs_generic_rw_release(data);
1623 }
1624
1625 static void ff_layout_commit_record_layoutstats_start(struct rpc_task *task,
1626                 struct nfs_commit_data *cdata)
1627 {
1628         if (test_and_set_bit(NFS_IOHDR_STAT, &cdata->flags))
1629                 return;
1630         nfs4_ff_layout_stat_io_start_write(cdata->inode,
1631                         FF_LAYOUT_COMP(cdata->lseg, cdata->ds_commit_index),
1632                         0, task->tk_start);
1633 }
1634
1635 static void ff_layout_commit_record_layoutstats_done(struct rpc_task *task,
1636                 struct nfs_commit_data *cdata)
1637 {
1638         struct nfs_page *req;
1639         __u64 count = 0;
1640
1641         if (!test_and_clear_bit(NFS_IOHDR_STAT, &cdata->flags))
1642                 return;
1643
1644         if (task->tk_status == 0) {
1645                 list_for_each_entry(req, &cdata->pages, wb_list)
1646                         count += req->wb_bytes;
1647         }
1648         nfs4_ff_layout_stat_io_end_write(task,
1649                         FF_LAYOUT_COMP(cdata->lseg, cdata->ds_commit_index),
1650                         count, count, NFS_FILE_SYNC);
1651 }
1652
1653 static void ff_layout_commit_prepare_common(struct rpc_task *task,
1654                 struct nfs_commit_data *cdata)
1655 {
1656         ff_layout_commit_record_layoutstats_start(task, cdata);
1657 }
1658
1659 static void ff_layout_commit_prepare_v3(struct rpc_task *task, void *data)
1660 {
1661         ff_layout_commit_prepare_common(task, data);
1662         rpc_call_start(task);
1663 }
1664
1665 static void ff_layout_commit_prepare_v4(struct rpc_task *task, void *data)
1666 {
1667         struct nfs_commit_data *wdata = data;
1668
1669         if (ff_layout_setup_sequence(wdata->ds_clp,
1670                                  &wdata->args.seq_args,
1671                                  &wdata->res.seq_res,
1672                                  task))
1673                 return;
1674         ff_layout_commit_prepare_common(task, data);
1675 }
1676
1677 static void ff_layout_commit_done(struct rpc_task *task, void *data)
1678 {
1679         pnfs_generic_write_commit_done(task, data);
1680 }
1681
1682 static void ff_layout_commit_count_stats(struct rpc_task *task, void *data)
1683 {
1684         struct nfs_commit_data *cdata = data;
1685
1686         ff_layout_commit_record_layoutstats_done(task, cdata);
1687         rpc_count_iostats_metrics(task,
1688             &NFS_CLIENT(cdata->inode)->cl_metrics[NFSPROC4_CLNT_COMMIT]);
1689 }
1690
1691 static void ff_layout_commit_release(void *data)
1692 {
1693         struct nfs_commit_data *cdata = data;
1694
1695         ff_layout_commit_record_layoutstats_done(&cdata->task, cdata);
1696         pnfs_generic_commit_release(data);
1697 }
1698
1699 static const struct rpc_call_ops ff_layout_read_call_ops_v3 = {
1700         .rpc_call_prepare = ff_layout_read_prepare_v3,
1701         .rpc_call_done = ff_layout_read_call_done,
1702         .rpc_count_stats = ff_layout_read_count_stats,
1703         .rpc_release = ff_layout_read_release,
1704 };
1705
1706 static const struct rpc_call_ops ff_layout_read_call_ops_v4 = {
1707         .rpc_call_prepare = ff_layout_read_prepare_v4,
1708         .rpc_call_done = ff_layout_read_call_done,
1709         .rpc_count_stats = ff_layout_read_count_stats,
1710         .rpc_release = ff_layout_read_release,
1711 };
1712
1713 static const struct rpc_call_ops ff_layout_write_call_ops_v3 = {
1714         .rpc_call_prepare = ff_layout_write_prepare_v3,
1715         .rpc_call_done = ff_layout_write_call_done,
1716         .rpc_count_stats = ff_layout_write_count_stats,
1717         .rpc_release = ff_layout_write_release,
1718 };
1719
1720 static const struct rpc_call_ops ff_layout_write_call_ops_v4 = {
1721         .rpc_call_prepare = ff_layout_write_prepare_v4,
1722         .rpc_call_done = ff_layout_write_call_done,
1723         .rpc_count_stats = ff_layout_write_count_stats,
1724         .rpc_release = ff_layout_write_release,
1725 };
1726
1727 static const struct rpc_call_ops ff_layout_commit_call_ops_v3 = {
1728         .rpc_call_prepare = ff_layout_commit_prepare_v3,
1729         .rpc_call_done = ff_layout_commit_done,
1730         .rpc_count_stats = ff_layout_commit_count_stats,
1731         .rpc_release = ff_layout_commit_release,
1732 };
1733
1734 static const struct rpc_call_ops ff_layout_commit_call_ops_v4 = {
1735         .rpc_call_prepare = ff_layout_commit_prepare_v4,
1736         .rpc_call_done = ff_layout_commit_done,
1737         .rpc_count_stats = ff_layout_commit_count_stats,
1738         .rpc_release = ff_layout_commit_release,
1739 };
1740
1741 static enum pnfs_try_status
1742 ff_layout_read_pagelist(struct nfs_pgio_header *hdr)
1743 {
1744         struct pnfs_layout_segment *lseg = hdr->lseg;
1745         struct nfs4_pnfs_ds *ds;
1746         struct rpc_clnt *ds_clnt;
1747         struct rpc_cred *ds_cred;
1748         loff_t offset = hdr->args.offset;
1749         u32 idx = hdr->pgio_mirror_idx;
1750         int vers;
1751         struct nfs_fh *fh;
1752
1753         dprintk("--> %s ino %lu pgbase %u req %Zu@%llu\n",
1754                 __func__, hdr->inode->i_ino,
1755                 hdr->args.pgbase, (size_t)hdr->args.count, offset);
1756
1757         ds = nfs4_ff_layout_prepare_ds(lseg, idx, false);
1758         if (!ds)
1759                 goto out_failed;
1760
1761         ds_clnt = nfs4_ff_find_or_create_ds_client(lseg, idx, ds->ds_clp,
1762                                                    hdr->inode);
1763         if (IS_ERR(ds_clnt))
1764                 goto out_failed;
1765
1766         ds_cred = ff_layout_get_ds_cred(lseg, idx, hdr->cred);
1767         if (!ds_cred)
1768                 goto out_failed;
1769
1770         vers = nfs4_ff_layout_ds_version(lseg, idx);
1771
1772         dprintk("%s USE DS: %s cl_count %d vers %d\n", __func__,
1773                 ds->ds_remotestr, atomic_read(&ds->ds_clp->cl_count), vers);
1774
1775         hdr->pgio_done_cb = ff_layout_read_done_cb;
1776         atomic_inc(&ds->ds_clp->cl_count);
1777         hdr->ds_clp = ds->ds_clp;
1778         fh = nfs4_ff_layout_select_ds_fh(lseg, idx);
1779         if (fh)
1780                 hdr->args.fh = fh;
1781         /*
1782          * Note that if we ever decide to split across DSes,
1783          * then we may need to handle dense-like offsets.
1784          */
1785         hdr->args.offset = offset;
1786         hdr->mds_offset = offset;
1787
1788         /* Perform an asynchronous read to ds */
1789         nfs_initiate_pgio(ds_clnt, hdr, ds_cred, ds->ds_clp->rpc_ops,
1790                           vers == 3 ? &ff_layout_read_call_ops_v3 :
1791                                       &ff_layout_read_call_ops_v4,
1792                           0, RPC_TASK_SOFTCONN);
1793         put_rpccred(ds_cred);
1794         return PNFS_ATTEMPTED;
1795
1796 out_failed:
1797         if (ff_layout_avoid_mds_available_ds(lseg))
1798                 return PNFS_TRY_AGAIN;
1799         return PNFS_NOT_ATTEMPTED;
1800 }
1801
1802 /* Perform async writes. */
1803 static enum pnfs_try_status
1804 ff_layout_write_pagelist(struct nfs_pgio_header *hdr, int sync)
1805 {
1806         struct pnfs_layout_segment *lseg = hdr->lseg;
1807         struct nfs4_pnfs_ds *ds;
1808         struct rpc_clnt *ds_clnt;
1809         struct rpc_cred *ds_cred;
1810         loff_t offset = hdr->args.offset;
1811         int vers;
1812         struct nfs_fh *fh;
1813         int idx = hdr->pgio_mirror_idx;
1814
1815         ds = nfs4_ff_layout_prepare_ds(lseg, idx, true);
1816         if (!ds)
1817                 return PNFS_NOT_ATTEMPTED;
1818
1819         ds_clnt = nfs4_ff_find_or_create_ds_client(lseg, idx, ds->ds_clp,
1820                                                    hdr->inode);
1821         if (IS_ERR(ds_clnt))
1822                 return PNFS_NOT_ATTEMPTED;
1823
1824         ds_cred = ff_layout_get_ds_cred(lseg, idx, hdr->cred);
1825         if (!ds_cred)
1826                 return PNFS_NOT_ATTEMPTED;
1827
1828         vers = nfs4_ff_layout_ds_version(lseg, idx);
1829
1830         dprintk("%s ino %lu sync %d req %Zu@%llu DS: %s cl_count %d vers %d\n",
1831                 __func__, hdr->inode->i_ino, sync, (size_t) hdr->args.count,
1832                 offset, ds->ds_remotestr, atomic_read(&ds->ds_clp->cl_count),
1833                 vers);
1834
1835         hdr->pgio_done_cb = ff_layout_write_done_cb;
1836         atomic_inc(&ds->ds_clp->cl_count);
1837         hdr->ds_clp = ds->ds_clp;
1838         hdr->ds_commit_idx = idx;
1839         fh = nfs4_ff_layout_select_ds_fh(lseg, idx);
1840         if (fh)
1841                 hdr->args.fh = fh;
1842
1843         /*
1844          * Note that if we ever decide to split across DSes,
1845          * then we may need to handle dense-like offsets.
1846          */
1847         hdr->args.offset = offset;
1848
1849         /* Perform an asynchronous write */
1850         nfs_initiate_pgio(ds_clnt, hdr, ds_cred, ds->ds_clp->rpc_ops,
1851                           vers == 3 ? &ff_layout_write_call_ops_v3 :
1852                                       &ff_layout_write_call_ops_v4,
1853                           sync, RPC_TASK_SOFTCONN);
1854         put_rpccred(ds_cred);
1855         return PNFS_ATTEMPTED;
1856 }
1857
1858 static u32 calc_ds_index_from_commit(struct pnfs_layout_segment *lseg, u32 i)
1859 {
1860         return i;
1861 }
1862
1863 static struct nfs_fh *
1864 select_ds_fh_from_commit(struct pnfs_layout_segment *lseg, u32 i)
1865 {
1866         struct nfs4_ff_layout_segment *flseg = FF_LAYOUT_LSEG(lseg);
1867
1868         /* FIXME: Assume that there is only one NFS version available
1869          * for the DS.
1870          */
1871         return &flseg->mirror_array[i]->fh_versions[0];
1872 }
1873
1874 static int ff_layout_initiate_commit(struct nfs_commit_data *data, int how)
1875 {
1876         struct pnfs_layout_segment *lseg = data->lseg;
1877         struct nfs4_pnfs_ds *ds;
1878         struct rpc_clnt *ds_clnt;
1879         struct rpc_cred *ds_cred;
1880         u32 idx;
1881         int vers, ret;
1882         struct nfs_fh *fh;
1883
1884         idx = calc_ds_index_from_commit(lseg, data->ds_commit_index);
1885         ds = nfs4_ff_layout_prepare_ds(lseg, idx, true);
1886         if (!ds)
1887                 goto out_err;
1888
1889         ds_clnt = nfs4_ff_find_or_create_ds_client(lseg, idx, ds->ds_clp,
1890                                                    data->inode);
1891         if (IS_ERR(ds_clnt))
1892                 goto out_err;
1893
1894         ds_cred = ff_layout_get_ds_cred(lseg, idx, data->cred);
1895         if (!ds_cred)
1896                 goto out_err;
1897
1898         vers = nfs4_ff_layout_ds_version(lseg, idx);
1899
1900         dprintk("%s ino %lu, how %d cl_count %d vers %d\n", __func__,
1901                 data->inode->i_ino, how, atomic_read(&ds->ds_clp->cl_count),
1902                 vers);
1903         data->commit_done_cb = ff_layout_commit_done_cb;
1904         data->cred = ds_cred;
1905         atomic_inc(&ds->ds_clp->cl_count);
1906         data->ds_clp = ds->ds_clp;
1907         fh = select_ds_fh_from_commit(lseg, data->ds_commit_index);
1908         if (fh)
1909                 data->args.fh = fh;
1910
1911         ret = nfs_initiate_commit(ds_clnt, data, ds->ds_clp->rpc_ops,
1912                                    vers == 3 ? &ff_layout_commit_call_ops_v3 :
1913                                                &ff_layout_commit_call_ops_v4,
1914                                    how, RPC_TASK_SOFTCONN);
1915         put_rpccred(ds_cred);
1916         return ret;
1917 out_err:
1918         pnfs_generic_prepare_to_resend_writes(data);
1919         pnfs_generic_commit_release(data);
1920         return -EAGAIN;
1921 }
1922
1923 static int
1924 ff_layout_commit_pagelist(struct inode *inode, struct list_head *mds_pages,
1925                            int how, struct nfs_commit_info *cinfo)
1926 {
1927         return pnfs_generic_commit_pagelist(inode, mds_pages, how, cinfo,
1928                                             ff_layout_initiate_commit);
1929 }
1930
1931 static struct pnfs_ds_commit_info *
1932 ff_layout_get_ds_info(struct inode *inode)
1933 {
1934         struct pnfs_layout_hdr *layout = NFS_I(inode)->layout;
1935
1936         if (layout == NULL)
1937                 return NULL;
1938
1939         return &FF_LAYOUT_FROM_HDR(layout)->commit_info;
1940 }
1941
1942 static void
1943 ff_layout_free_deviceid_node(struct nfs4_deviceid_node *d)
1944 {
1945         nfs4_ff_layout_free_deviceid(container_of(d, struct nfs4_ff_layout_ds,
1946                                                   id_node));
1947 }
1948
1949 static int ff_layout_encode_ioerr(struct nfs4_flexfile_layout *flo,
1950                                   struct xdr_stream *xdr,
1951                                   const struct nfs4_layoutreturn_args *args,
1952                                   const struct nfs4_flexfile_layoutreturn_args *ff_args)
1953 {
1954         __be32 *start;
1955
1956         start = xdr_reserve_space(xdr, 4);
1957         if (unlikely(!start))
1958                 return -E2BIG;
1959
1960         *start = cpu_to_be32(ff_args->num_errors);
1961         /* This assume we always return _ALL_ layouts */
1962         return ff_layout_encode_ds_ioerr(xdr, &ff_args->errors);
1963 }
1964
1965 static void
1966 encode_opaque_fixed(struct xdr_stream *xdr, const void *buf, size_t len)
1967 {
1968         __be32 *p;
1969
1970         p = xdr_reserve_space(xdr, len);
1971         xdr_encode_opaque_fixed(p, buf, len);
1972 }
1973
1974 static void
1975 ff_layout_encode_ff_iostat_head(struct xdr_stream *xdr,
1976                             const nfs4_stateid *stateid,
1977                             const struct nfs42_layoutstat_devinfo *devinfo)
1978 {
1979         __be32 *p;
1980
1981         p = xdr_reserve_space(xdr, 8 + 8);
1982         p = xdr_encode_hyper(p, devinfo->offset);
1983         p = xdr_encode_hyper(p, devinfo->length);
1984         encode_opaque_fixed(xdr, stateid->data, NFS4_STATEID_SIZE);
1985         p = xdr_reserve_space(xdr, 4*8);
1986         p = xdr_encode_hyper(p, devinfo->read_count);
1987         p = xdr_encode_hyper(p, devinfo->read_bytes);
1988         p = xdr_encode_hyper(p, devinfo->write_count);
1989         p = xdr_encode_hyper(p, devinfo->write_bytes);
1990         encode_opaque_fixed(xdr, devinfo->dev_id.data, NFS4_DEVICEID4_SIZE);
1991 }
1992
1993 static void
1994 ff_layout_encode_ff_iostat(struct xdr_stream *xdr,
1995                             const nfs4_stateid *stateid,
1996                             const struct nfs42_layoutstat_devinfo *devinfo)
1997 {
1998         ff_layout_encode_ff_iostat_head(xdr, stateid, devinfo);
1999         ff_layout_encode_ff_layoutupdate(xdr, devinfo,
2000                         devinfo->ld_private.data);
2001 }
2002
2003 /* report nothing for now */
2004 static void ff_layout_encode_iostats_array(struct xdr_stream *xdr,
2005                 const struct nfs4_layoutreturn_args *args,
2006                 struct nfs4_flexfile_layoutreturn_args *ff_args)
2007 {
2008         __be32 *p;
2009         int i;
2010
2011         p = xdr_reserve_space(xdr, 4);
2012         *p = cpu_to_be32(ff_args->num_dev);
2013         for (i = 0; i < ff_args->num_dev; i++)
2014                 ff_layout_encode_ff_iostat(xdr,
2015                                 &args->layout->plh_stateid,
2016                                 &ff_args->devinfo[i]);
2017 }
2018
2019 static void
2020 ff_layout_free_iostats_array(struct nfs42_layoutstat_devinfo *devinfo,
2021                 unsigned int num_entries)
2022 {
2023         unsigned int i;
2024
2025         for (i = 0; i < num_entries; i++) {
2026                 if (!devinfo[i].ld_private.ops)
2027                         continue;
2028                 if (!devinfo[i].ld_private.ops->free)
2029                         continue;
2030                 devinfo[i].ld_private.ops->free(&devinfo[i].ld_private);
2031         }
2032 }
2033
2034 static struct nfs4_deviceid_node *
2035 ff_layout_alloc_deviceid_node(struct nfs_server *server,
2036                               struct pnfs_device *pdev, gfp_t gfp_flags)
2037 {
2038         struct nfs4_ff_layout_ds *dsaddr;
2039
2040         dsaddr = nfs4_ff_alloc_deviceid_node(server, pdev, gfp_flags);
2041         if (!dsaddr)
2042                 return NULL;
2043         return &dsaddr->id_node;
2044 }
2045
2046 static void
2047 ff_layout_encode_layoutreturn(struct xdr_stream *xdr,
2048                 const void *voidargs,
2049                 const struct nfs4_xdr_opaque_data *ff_opaque)
2050 {
2051         const struct nfs4_layoutreturn_args *args = voidargs;
2052         struct pnfs_layout_hdr *lo = args->layout;
2053         struct nfs4_flexfile_layout *flo = FF_LAYOUT_FROM_HDR(lo);
2054         __be32 *start;
2055
2056         dprintk("%s: Begin\n", __func__);
2057         start = xdr_reserve_space(xdr, 4);
2058         BUG_ON(!start);
2059
2060         ff_layout_encode_ioerr(flo, xdr, args, ff_opaque->data);
2061         ff_layout_encode_iostats_array(xdr, args, ff_opaque->data);
2062
2063         *start = cpu_to_be32((xdr->p - start - 1) * 4);
2064         dprintk("%s: Return\n", __func__);
2065 }
2066
2067 static void
2068 ff_layout_free_layoutreturn(struct nfs4_xdr_opaque_data *args)
2069 {
2070         struct nfs4_flexfile_layoutreturn_args *ff_args;
2071
2072         if (!args->data)
2073                 return;
2074         ff_args = args->data;
2075         args->data = NULL;
2076
2077         ff_layout_free_ds_ioerr(&ff_args->errors);
2078         ff_layout_free_iostats_array(ff_args->devinfo, ff_args->num_dev);
2079
2080         kfree(ff_args);
2081 }
2082
2083 const struct nfs4_xdr_opaque_ops layoutreturn_ops = {
2084         .encode = ff_layout_encode_layoutreturn,
2085         .free = ff_layout_free_layoutreturn,
2086 };
2087
2088 static int
2089 ff_layout_prepare_layoutreturn(struct nfs4_layoutreturn_args *args)
2090 {
2091         struct nfs4_flexfile_layoutreturn_args *ff_args;
2092         struct nfs4_flexfile_layout *ff_layout = FF_LAYOUT_FROM_HDR(args->layout);
2093
2094         ff_args = kmalloc(sizeof(*ff_args), GFP_KERNEL);
2095         if (!ff_args)
2096                 return -ENOMEM;
2097
2098         INIT_LIST_HEAD(&ff_args->errors);
2099         ff_args->num_errors = ff_layout_fetch_ds_ioerr(args->layout,
2100                         &args->range, &ff_args->errors,
2101                         FF_LAYOUTRETURN_MAXERR);
2102
2103         spin_lock(&args->inode->i_lock);
2104         ff_args->num_dev = ff_layout_mirror_prepare_stats(&ff_layout->generic_hdr,
2105                         &ff_args->devinfo[0], ARRAY_SIZE(ff_args->devinfo));
2106         spin_unlock(&args->inode->i_lock);
2107
2108         args->ld_private->ops = &layoutreturn_ops;
2109         args->ld_private->data = ff_args;
2110         return 0;
2111 }
2112
2113 static int
2114 ff_layout_ntop4(const struct sockaddr *sap, char *buf, const size_t buflen)
2115 {
2116         const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
2117
2118         return snprintf(buf, buflen, "%pI4", &sin->sin_addr);
2119 }
2120
2121 static size_t
2122 ff_layout_ntop6_noscopeid(const struct sockaddr *sap, char *buf,
2123                           const int buflen)
2124 {
2125         const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
2126         const struct in6_addr *addr = &sin6->sin6_addr;
2127
2128         /*
2129          * RFC 4291, Section 2.2.2
2130          *
2131          * Shorthanded ANY address
2132          */
2133         if (ipv6_addr_any(addr))
2134                 return snprintf(buf, buflen, "::");
2135
2136         /*
2137          * RFC 4291, Section 2.2.2
2138          *
2139          * Shorthanded loopback address
2140          */
2141         if (ipv6_addr_loopback(addr))
2142                 return snprintf(buf, buflen, "::1");
2143
2144         /*
2145          * RFC 4291, Section 2.2.3
2146          *
2147          * Special presentation address format for mapped v4
2148          * addresses.
2149          */
2150         if (ipv6_addr_v4mapped(addr))
2151                 return snprintf(buf, buflen, "::ffff:%pI4",
2152                                         &addr->s6_addr32[3]);
2153
2154         /*
2155          * RFC 4291, Section 2.2.1
2156          */
2157         return snprintf(buf, buflen, "%pI6c", addr);
2158 }
2159
2160 /* Derived from rpc_sockaddr2uaddr */
2161 static void
2162 ff_layout_encode_netaddr(struct xdr_stream *xdr, struct nfs4_pnfs_ds_addr *da)
2163 {
2164         struct sockaddr *sap = (struct sockaddr *)&da->da_addr;
2165         char portbuf[RPCBIND_MAXUADDRPLEN];
2166         char addrbuf[RPCBIND_MAXUADDRLEN];
2167         char *netid;
2168         unsigned short port;
2169         int len, netid_len;
2170         __be32 *p;
2171
2172         switch (sap->sa_family) {
2173         case AF_INET:
2174                 if (ff_layout_ntop4(sap, addrbuf, sizeof(addrbuf)) == 0)
2175                         return;
2176                 port = ntohs(((struct sockaddr_in *)sap)->sin_port);
2177                 netid = "tcp";
2178                 netid_len = 3;
2179                 break;
2180         case AF_INET6:
2181                 if (ff_layout_ntop6_noscopeid(sap, addrbuf, sizeof(addrbuf)) == 0)
2182                         return;
2183                 port = ntohs(((struct sockaddr_in6 *)sap)->sin6_port);
2184                 netid = "tcp6";
2185                 netid_len = 4;
2186                 break;
2187         default:
2188                 /* we only support tcp and tcp6 */
2189                 WARN_ON_ONCE(1);
2190                 return;
2191         }
2192
2193         snprintf(portbuf, sizeof(portbuf), ".%u.%u", port >> 8, port & 0xff);
2194         len = strlcat(addrbuf, portbuf, sizeof(addrbuf));
2195
2196         p = xdr_reserve_space(xdr, 4 + netid_len);
2197         xdr_encode_opaque(p, netid, netid_len);
2198
2199         p = xdr_reserve_space(xdr, 4 + len);
2200         xdr_encode_opaque(p, addrbuf, len);
2201 }
2202
2203 static void
2204 ff_layout_encode_nfstime(struct xdr_stream *xdr,
2205                          ktime_t t)
2206 {
2207         struct timespec64 ts;
2208         __be32 *p;
2209
2210         p = xdr_reserve_space(xdr, 12);
2211         ts = ktime_to_timespec64(t);
2212         p = xdr_encode_hyper(p, ts.tv_sec);
2213         *p++ = cpu_to_be32(ts.tv_nsec);
2214 }
2215
2216 static void
2217 ff_layout_encode_io_latency(struct xdr_stream *xdr,
2218                             struct nfs4_ff_io_stat *stat)
2219 {
2220         __be32 *p;
2221
2222         p = xdr_reserve_space(xdr, 5 * 8);
2223         p = xdr_encode_hyper(p, stat->ops_requested);
2224         p = xdr_encode_hyper(p, stat->bytes_requested);
2225         p = xdr_encode_hyper(p, stat->ops_completed);
2226         p = xdr_encode_hyper(p, stat->bytes_completed);
2227         p = xdr_encode_hyper(p, stat->bytes_not_delivered);
2228         ff_layout_encode_nfstime(xdr, stat->total_busy_time);
2229         ff_layout_encode_nfstime(xdr, stat->aggregate_completion_time);
2230 }
2231
2232 static void
2233 ff_layout_encode_ff_layoutupdate(struct xdr_stream *xdr,
2234                               const struct nfs42_layoutstat_devinfo *devinfo,
2235                               struct nfs4_ff_layout_mirror *mirror)
2236 {
2237         struct nfs4_pnfs_ds_addr *da;
2238         struct nfs4_pnfs_ds *ds = mirror->mirror_ds->ds;
2239         struct nfs_fh *fh = &mirror->fh_versions[0];
2240         __be32 *p;
2241
2242         da = list_first_entry(&ds->ds_addrs, struct nfs4_pnfs_ds_addr, da_node);
2243         dprintk("%s: DS %s: encoding address %s\n",
2244                 __func__, ds->ds_remotestr, da->da_remotestr);
2245         /* netaddr4 */
2246         ff_layout_encode_netaddr(xdr, da);
2247         /* nfs_fh4 */
2248         p = xdr_reserve_space(xdr, 4 + fh->size);
2249         xdr_encode_opaque(p, fh->data, fh->size);
2250         /* ff_io_latency4 read */
2251         spin_lock(&mirror->lock);
2252         ff_layout_encode_io_latency(xdr, &mirror->read_stat.io_stat);
2253         /* ff_io_latency4 write */
2254         ff_layout_encode_io_latency(xdr, &mirror->write_stat.io_stat);
2255         spin_unlock(&mirror->lock);
2256         /* nfstime4 */
2257         ff_layout_encode_nfstime(xdr, ktime_sub(ktime_get(), mirror->start_time));
2258         /* bool */
2259         p = xdr_reserve_space(xdr, 4);
2260         *p = cpu_to_be32(false);
2261 }
2262
2263 static void
2264 ff_layout_encode_layoutstats(struct xdr_stream *xdr, const void *args,
2265                              const struct nfs4_xdr_opaque_data *opaque)
2266 {
2267         struct nfs42_layoutstat_devinfo *devinfo = container_of(opaque,
2268                         struct nfs42_layoutstat_devinfo, ld_private);
2269         __be32 *start;
2270
2271         /* layoutupdate length */
2272         start = xdr_reserve_space(xdr, 4);
2273         ff_layout_encode_ff_layoutupdate(xdr, devinfo, opaque->data);
2274
2275         *start = cpu_to_be32((xdr->p - start - 1) * 4);
2276 }
2277
2278 static void
2279 ff_layout_free_layoutstats(struct nfs4_xdr_opaque_data *opaque)
2280 {
2281         struct nfs4_ff_layout_mirror *mirror = opaque->data;
2282
2283         ff_layout_put_mirror(mirror);
2284 }
2285
2286 static const struct nfs4_xdr_opaque_ops layoutstat_ops = {
2287         .encode = ff_layout_encode_layoutstats,
2288         .free   = ff_layout_free_layoutstats,
2289 };
2290
2291 static int
2292 ff_layout_mirror_prepare_stats(struct pnfs_layout_hdr *lo,
2293                                struct nfs42_layoutstat_devinfo *devinfo,
2294                                int dev_limit)
2295 {
2296         struct nfs4_flexfile_layout *ff_layout = FF_LAYOUT_FROM_HDR(lo);
2297         struct nfs4_ff_layout_mirror *mirror;
2298         struct nfs4_deviceid_node *dev;
2299         int i = 0;
2300
2301         list_for_each_entry(mirror, &ff_layout->mirrors, mirrors) {
2302                 if (i >= dev_limit)
2303                         break;
2304                 if (IS_ERR_OR_NULL(mirror->mirror_ds))
2305                         continue;
2306                 if (!test_and_clear_bit(NFS4_FF_MIRROR_STAT_AVAIL, &mirror->flags))
2307                         continue;
2308                 /* mirror refcount put in cleanup_layoutstats */
2309                 if (!atomic_inc_not_zero(&mirror->ref))
2310                         continue;
2311                 dev = &mirror->mirror_ds->id_node;
2312                 memcpy(&devinfo->dev_id, &dev->deviceid, NFS4_DEVICEID4_SIZE);
2313                 devinfo->offset = 0;
2314                 devinfo->length = NFS4_MAX_UINT64;
2315                 spin_lock(&mirror->lock);
2316                 devinfo->read_count = mirror->read_stat.io_stat.ops_completed;
2317                 devinfo->read_bytes = mirror->read_stat.io_stat.bytes_completed;
2318                 devinfo->write_count = mirror->write_stat.io_stat.ops_completed;
2319                 devinfo->write_bytes = mirror->write_stat.io_stat.bytes_completed;
2320                 spin_unlock(&mirror->lock);
2321                 devinfo->layout_type = LAYOUT_FLEX_FILES;
2322                 devinfo->ld_private.ops = &layoutstat_ops;
2323                 devinfo->ld_private.data = mirror;
2324
2325                 devinfo++;
2326                 i++;
2327         }
2328         return i;
2329 }
2330
2331 static int
2332 ff_layout_prepare_layoutstats(struct nfs42_layoutstat_args *args)
2333 {
2334         struct nfs4_flexfile_layout *ff_layout;
2335         const int dev_count = PNFS_LAYOUTSTATS_MAXDEV;
2336
2337         /* For now, send at most PNFS_LAYOUTSTATS_MAXDEV statistics */
2338         args->devinfo = kmalloc_array(dev_count, sizeof(*args->devinfo), GFP_NOIO);
2339         if (!args->devinfo)
2340                 return -ENOMEM;
2341
2342         spin_lock(&args->inode->i_lock);
2343         ff_layout = FF_LAYOUT_FROM_HDR(NFS_I(args->inode)->layout);
2344         args->num_dev = ff_layout_mirror_prepare_stats(&ff_layout->generic_hdr,
2345                         &args->devinfo[0], dev_count);
2346         spin_unlock(&args->inode->i_lock);
2347         if (!args->num_dev) {
2348                 kfree(args->devinfo);
2349                 args->devinfo = NULL;
2350                 return -ENOENT;
2351         }
2352
2353         return 0;
2354 }
2355
2356 static struct pnfs_layoutdriver_type flexfilelayout_type = {
2357         .id                     = LAYOUT_FLEX_FILES,
2358         .name                   = "LAYOUT_FLEX_FILES",
2359         .owner                  = THIS_MODULE,
2360         .alloc_layout_hdr       = ff_layout_alloc_layout_hdr,
2361         .free_layout_hdr        = ff_layout_free_layout_hdr,
2362         .alloc_lseg             = ff_layout_alloc_lseg,
2363         .free_lseg              = ff_layout_free_lseg,
2364         .add_lseg               = ff_layout_add_lseg,
2365         .pg_read_ops            = &ff_layout_pg_read_ops,
2366         .pg_write_ops           = &ff_layout_pg_write_ops,
2367         .get_ds_info            = ff_layout_get_ds_info,
2368         .free_deviceid_node     = ff_layout_free_deviceid_node,
2369         .mark_request_commit    = pnfs_layout_mark_request_commit,
2370         .clear_request_commit   = pnfs_generic_clear_request_commit,
2371         .scan_commit_lists      = pnfs_generic_scan_commit_lists,
2372         .recover_commit_reqs    = pnfs_generic_recover_commit_reqs,
2373         .commit_pagelist        = ff_layout_commit_pagelist,
2374         .read_pagelist          = ff_layout_read_pagelist,
2375         .write_pagelist         = ff_layout_write_pagelist,
2376         .alloc_deviceid_node    = ff_layout_alloc_deviceid_node,
2377         .prepare_layoutreturn   = ff_layout_prepare_layoutreturn,
2378         .sync                   = pnfs_nfs_generic_sync,
2379         .prepare_layoutstats    = ff_layout_prepare_layoutstats,
2380 };
2381
2382 static int __init nfs4flexfilelayout_init(void)
2383 {
2384         printk(KERN_INFO "%s: NFSv4 Flexfile Layout Driver Registering...\n",
2385                __func__);
2386         if (!ff_zero_group) {
2387                 ff_zero_group = groups_alloc(0);
2388                 if (!ff_zero_group)
2389                         return -ENOMEM;
2390         }
2391         return pnfs_register_layoutdriver(&flexfilelayout_type);
2392 }
2393
2394 static void __exit nfs4flexfilelayout_exit(void)
2395 {
2396         printk(KERN_INFO "%s: NFSv4 Flexfile Layout Driver Unregistering...\n",
2397                __func__);
2398         pnfs_unregister_layoutdriver(&flexfilelayout_type);
2399         if (ff_zero_group) {
2400                 put_group_info(ff_zero_group);
2401                 ff_zero_group = NULL;
2402         }
2403 }
2404
2405 MODULE_ALIAS("nfs-layouttype4-4");
2406
2407 MODULE_LICENSE("GPL");
2408 MODULE_DESCRIPTION("The NFSv4 flexfile layout driver");
2409
2410 module_init(nfs4flexfilelayout_init);
2411 module_exit(nfs4flexfilelayout_exit);