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 <[email protected]>
   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 (refcount_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                 refcount_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 && refcount_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                 rc = -EIO;
 458                 p = xdr_inline_decode(&stream, 4);
 459                 if (!p)
 460                         goto out_err_free;
 461                 fh_count = be32_to_cpup(p);
 462
 463                 fls->mirror_array[i]->fh_versions =
 464                         kcalloc(fh_count, sizeof(struct nfs_fh),
 465                                 gfp_flags);
 466                 if (fls->mirror_array[i]->fh_versions == NULL) {
 467                         rc = -ENOMEM;
 468                         goto out_err_free;
 469                 }
 470
 471                 for (j = 0; j < fh_count; j++) {
 472                         rc = decode_nfs_fh(&stream,
 473                                            &fls->mirror_array[i]->fh_versions[j]);
 474                         if (rc)
 475                                 goto out_err_free;
 476                 }
 477
 478                 fls->mirror_array[i]->fh_versions_cnt = fh_count;
 479
 480                 /* user */
 481                 rc = decode_name(&stream, &id);
 482                 if (rc)
 483                         goto out_err_free;
 484
 485                 acred.uid = make_kuid(&init_user_ns, id);
 486
 487                 /* group */
 488                 rc = decode_name(&stream, &id);
 489                 if (rc)
 490                         goto out_err_free;
 491
 492                 acred.gid = make_kgid(&init_user_ns, id);
 493
 494                 /* find the cred for it */
 495                 rcu_assign_pointer(cred, rpc_lookup_generic_cred(&acred, 0, gfp_flags));
 496                 if (IS_ERR(cred)) {
 497                         rc = PTR_ERR(cred);
 498                         goto out_err_free;
 499                 }
 500
 501                 if (lgr->range.iomode == IOMODE_READ)
 502                         rcu_assign_pointer(fls->mirror_array[i]->ro_cred, cred);
 503                 else
 504                         rcu_assign_pointer(fls->mirror_array[i]->rw_cred, cred);
 505
 506                 mirror = ff_layout_add_mirror(lh, fls->mirror_array[i]);
 507                 if (mirror != fls->mirror_array[i]) {
 508                         /* swap cred ptrs so free_mirror will clean up old */
 509                         if (lgr->range.iomode == IOMODE_READ) {
 510                                 cred = xchg(&mirror->ro_cred, cred);
 511                                 rcu_assign_pointer(fls->mirror_array[i]->ro_cred, cred);
 512                         } else {
 513                                 cred = xchg(&mirror->rw_cred, cred);
 514                                 rcu_assign_pointer(fls->mirror_array[i]->rw_cred, cred);
 515                         }
 516                         ff_layout_free_mirror(fls->mirror_array[i]);
 517                         fls->mirror_array[i] = mirror;
 518                 }
 519
 520                 dprintk("%s: iomode %s uid %u gid %u\n", __func__,
 521                         lgr->range.iomode == IOMODE_READ ? "READ" : "RW",
 522                         from_kuid(&init_user_ns, acred.uid),
 523                         from_kgid(&init_user_ns, acred.gid));
 524         }
 525
 526         p = xdr_inline_decode(&stream, 4);
 527         if (!p)
 528                 goto out_sort_mirrors;
 529         fls->flags = be32_to_cpup(p);
 530
 531         p = xdr_inline_decode(&stream, 4);
 532         if (!p)
 533                 goto out_sort_mirrors;
 534         for (i=0; i < fls->mirror_array_cnt; i++)
 535                 fls->mirror_array[i]->report_interval = be32_to_cpup(p);
 536
 537 out_sort_mirrors:
 538         ff_layout_sort_mirrors(fls);
 539         rc = ff_layout_check_layout(lgr);
 540         if (rc)
 541                 goto out_err_free;
 542         ret = &fls->generic_hdr;
 543         dprintk("<-- %s (success)\n", __func__);
 544 out_free_page:
 545         __free_page(scratch);
 546         return ret;
 547 out_err_free:
 548         _ff_layout_free_lseg(fls);
 549         ret = ERR_PTR(rc);
 550         dprintk("<-- %s (%d)\n", __func__, rc);
 551         goto out_free_page;
 552 }
 553
 554 static bool ff_layout_has_rw_segments(struct pnfs_layout_hdr *layout)
 555 {
 556         struct pnfs_layout_segment *lseg;
 557
 558         list_for_each_entry(lseg, &layout->plh_segs, pls_list)
 559                 if (lseg->pls_range.iomode == IOMODE_RW)
 560                         return true;
 561
 562         return false;
 563 }
 564
 565 static void
 566 ff_layout_free_lseg(struct pnfs_layout_segment *lseg)
 567 {
 568         struct nfs4_ff_layout_segment *fls = FF_LAYOUT_LSEG(lseg);
 569
 570         dprintk("--> %s\n", __func__);
 571
 572         if (lseg->pls_range.iomode == IOMODE_RW) {
 573                 struct nfs4_flexfile_layout *ffl;
 574                 struct inode *inode;
 575
 576                 ffl = FF_LAYOUT_FROM_HDR(lseg->pls_layout);
 577                 inode = ffl->generic_hdr.plh_inode;
 578                 spin_lock(&inode->i_lock);
 579                 if (!ff_layout_has_rw_segments(lseg->pls_layout)) {
 580                         ffl->commit_info.nbuckets = 0;
 581                         kfree(ffl->commit_info.buckets);
 582                         ffl->commit_info.buckets = NULL;
 583                 }
 584                 spin_unlock(&inode->i_lock);
 585         }
 586         _ff_layout_free_lseg(fls);
 587 }
 588
 589 /* Return 1 until we have multiple lsegs support */
 590 static int
 591 ff_layout_get_lseg_count(struct nfs4_ff_layout_segment *fls)
 592 {
 593         return 1;
 594 }
 595
 596 static void
 597 nfs4_ff_start_busy_timer(struct nfs4_ff_busy_timer *timer, ktime_t now)
 598 {
 599         /* first IO request? */
 600         if (atomic_inc_return(&timer->n_ops) == 1) {
 601                 timer->start_time = now;
 602         }
 603 }
 604
 605 static ktime_t
 606 nfs4_ff_end_busy_timer(struct nfs4_ff_busy_timer *timer, ktime_t now)
 607 {
 608         ktime_t start;
 609
 610         if (atomic_dec_return(&timer->n_ops) < 0)
 611                 WARN_ON_ONCE(1);
 612
 613         start = timer->start_time;
 614         timer->start_time = now;
 615         return ktime_sub(now, start);
 616 }
 617
 618 static bool
 619 nfs4_ff_layoutstat_start_io(struct nfs4_ff_layout_mirror *mirror,
 620                             struct nfs4_ff_layoutstat *layoutstat,
 621                             ktime_t now)
 622 {
 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 (!mirror->start_time)
 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         pnfs_put_lseg(pgio->pg_lseg);
 816         pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
 817                                            req->wb_context,
 818                                            0,
 819                                            NFS4_MAX_UINT64,
 820                                            IOMODE_READ,
 821                                            strict_iomode,
 822                                            GFP_KERNEL);
 823         if (IS_ERR(pgio->pg_lseg)) {
 824                 pgio->pg_error = PTR_ERR(pgio->pg_lseg);
 825                 pgio->pg_lseg = NULL;
 826         }
 827 }
 828
 829 static void
 830 ff_layout_pg_init_read(struct nfs_pageio_descriptor *pgio,
 831                         struct nfs_page *req)
 832 {
 833         struct nfs_pgio_mirror *pgm;
 834         struct nfs4_ff_layout_mirror *mirror;
 835         struct nfs4_pnfs_ds *ds;
 836         int ds_idx;
 837
 838 retry:
 839         pnfs_generic_pg_check_layout(pgio);
 840         /* Use full layout for now */
 841         if (!pgio->pg_lseg) {
 842                 ff_layout_pg_get_read(pgio, req, false);
 843                 if (!pgio->pg_lseg)
 844                         goto out_nolseg;
 845         }
 846         if (ff_layout_avoid_read_on_rw(pgio->pg_lseg)) {
 847                 ff_layout_pg_get_read(pgio, req, true);
 848                 if (!pgio->pg_lseg)
 849                         goto out_nolseg;
 850         }
 851
 852         ds = ff_layout_choose_best_ds_for_read(pgio->pg_lseg, 0, &ds_idx);
 853         if (!ds) {
 854                 if (!ff_layout_no_fallback_to_mds(pgio->pg_lseg))
 855                         goto out_mds;
 856                 pnfs_put_lseg(pgio->pg_lseg);
 857                 pgio->pg_lseg = NULL;
 858                 /* Sleep for 1 second before retrying */
 859                 ssleep(1);
 860                 goto retry;
 861         }
 862
 863         mirror = FF_LAYOUT_COMP(pgio->pg_lseg, ds_idx);
 864
 865         pgio->pg_mirror_idx = ds_idx;
 866
 867         /* read always uses only one mirror - idx 0 for pgio layer */
 868         pgm = &pgio->pg_mirrors[0];
 869         pgm->pg_bsize = mirror->mirror_ds->ds_versions[0].rsize;
 870
 871         return;
 872 out_nolseg:
 873         if (pgio->pg_error < 0)
 874                 return;
 875 out_mds:
 876         pnfs_put_lseg(pgio->pg_lseg);
 877         pgio->pg_lseg = NULL;
 878         nfs_pageio_reset_read_mds(pgio);
 879 }
 880
 881 static void
 882 ff_layout_pg_init_write(struct nfs_pageio_descriptor *pgio,
 883                         struct nfs_page *req)
 884 {
 885         struct nfs4_ff_layout_mirror *mirror;
 886         struct nfs_pgio_mirror *pgm;
 887         struct nfs_commit_info cinfo;
 888         struct nfs4_pnfs_ds *ds;
 889         int i;
 890         int status;
 891
 892 retry:
 893         pnfs_generic_pg_check_layout(pgio);
 894         if (!pgio->pg_lseg) {
 895                 pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
 896                                                    req->wb_context,
 897                                                    0,
 898                                                    NFS4_MAX_UINT64,
 899                                                    IOMODE_RW,
 900                                                    false,
 901                                                    GFP_NOFS);
 902                 if (IS_ERR(pgio->pg_lseg)) {
 903                         pgio->pg_error = PTR_ERR(pgio->pg_lseg);
 904                         pgio->pg_lseg = NULL;
 905                         return;
 906                 }
 907         }
 908         /* If no lseg, fall back to write through mds */
 909         if (pgio->pg_lseg == NULL)
 910                 goto out_mds;
 911
 912         nfs_init_cinfo(&cinfo, pgio->pg_inode, pgio->pg_dreq);
 913         status = ff_layout_alloc_commit_info(pgio->pg_lseg, &cinfo, GFP_NOFS);
 914         if (status < 0)
 915                 goto out_mds;
 916
 917         /* Use a direct mapping of ds_idx to pgio mirror_idx */
 918         if (WARN_ON_ONCE(pgio->pg_mirror_count !=
 919             FF_LAYOUT_MIRROR_COUNT(pgio->pg_lseg)))
 920                 goto out_mds;
 921
 922         for (i = 0; i < pgio->pg_mirror_count; i++) {
 923                 ds = nfs4_ff_layout_prepare_ds(pgio->pg_lseg, i, true);
 924                 if (!ds) {
 925                         if (!ff_layout_no_fallback_to_mds(pgio->pg_lseg))
 926                                 goto out_mds;
 927                         pnfs_put_lseg(pgio->pg_lseg);
 928                         pgio->pg_lseg = NULL;
 929                         /* Sleep for 1 second before retrying */
 930                         ssleep(1);
 931                         goto retry;
 932                 }
 933                 pgm = &pgio->pg_mirrors[i];
 934                 mirror = FF_LAYOUT_COMP(pgio->pg_lseg, i);
 935                 pgm->pg_bsize = mirror->mirror_ds->ds_versions[0].wsize;
 936         }
 937
 938         return;
 939
 940 out_mds:
 941         pnfs_put_lseg(pgio->pg_lseg);
 942         pgio->pg_lseg = NULL;
 943         nfs_pageio_reset_write_mds(pgio);
 944 }
 945
 946 static unsigned int
 947 ff_layout_pg_get_mirror_count_write(struct nfs_pageio_descriptor *pgio,
 948                                     struct nfs_page *req)
 949 {
 950         if (!pgio->pg_lseg) {
 951                 pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
 952                                                    req->wb_context,
 953                                                    0,
 954                                                    NFS4_MAX_UINT64,
 955                                                    IOMODE_RW,
 956                                                    false,
 957                                                    GFP_NOFS);
 958                 if (IS_ERR(pgio->pg_lseg)) {
 959                         pgio->pg_error = PTR_ERR(pgio->pg_lseg);
 960                         pgio->pg_lseg = NULL;
 961                         goto out;
 962                 }
 963         }
 964         if (pgio->pg_lseg)
 965                 return FF_LAYOUT_MIRROR_COUNT(pgio->pg_lseg);
 966
 967         /* no lseg means that pnfs is not in use, so no mirroring here */
 968         nfs_pageio_reset_write_mds(pgio);
 969 out:
 970         return 1;
 971 }
 972
 973 static const struct nfs_pageio_ops ff_layout_pg_read_ops = {
 974         .pg_init = ff_layout_pg_init_read,
 975         .pg_test = pnfs_generic_pg_test,
 976         .pg_doio = pnfs_generic_pg_readpages,
 977         .pg_cleanup = pnfs_generic_pg_cleanup,
 978 };
 979
 980 static const struct nfs_pageio_ops ff_layout_pg_write_ops = {
 981         .pg_init = ff_layout_pg_init_write,
 982         .pg_test = pnfs_generic_pg_test,
 983         .pg_doio = pnfs_generic_pg_writepages,
 984         .pg_get_mirror_count = ff_layout_pg_get_mirror_count_write,
 985         .pg_cleanup = pnfs_generic_pg_cleanup,
 986 };
 987
 988 static void ff_layout_reset_write(struct nfs_pgio_header *hdr, bool retry_pnfs)
 989 {
 990         struct rpc_task *task = &hdr->task;
 991
 992         pnfs_layoutcommit_inode(hdr->inode, false);
 993
 994         if (retry_pnfs) {
 995                 dprintk("%s Reset task %5u for i/o through pNFS "
 996                         "(req %s/%llu, %u bytes @ offset %llu)\n", __func__,
 997                         hdr->task.tk_pid,
 998                         hdr->inode->i_sb->s_id,
 999                         (unsigned long long)NFS_FILEID(hdr->inode),
1000                         hdr->args.count,
1001                         (unsigned long long)hdr->args.offset);
1002
1003                 hdr->completion_ops->reschedule_io(hdr);
1004                 return;
1005         }
1006
1007         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
1008                 dprintk("%s Reset task %5u for i/o through MDS "
1009                         "(req %s/%llu, %u bytes @ offset %llu)\n", __func__,
1010                         hdr->task.tk_pid,
1011                         hdr->inode->i_sb->s_id,
1012                         (unsigned long long)NFS_FILEID(hdr->inode),
1013                         hdr->args.count,
1014                         (unsigned long long)hdr->args.offset);
1015
1016                 task->tk_status = pnfs_write_done_resend_to_mds(hdr);
1017         }
1018 }
1019
1020 static void ff_layout_reset_read(struct nfs_pgio_header *hdr)
1021 {
1022         struct rpc_task *task = &hdr->task;
1023
1024         pnfs_layoutcommit_inode(hdr->inode, false);
1025
1026         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
1027                 dprintk("%s Reset task %5u for i/o through MDS "
1028                         "(req %s/%llu, %u bytes @ offset %llu)\n", __func__,
1029                         hdr->task.tk_pid,
1030                         hdr->inode->i_sb->s_id,
1031                         (unsigned long long)NFS_FILEID(hdr->inode),
1032                         hdr->args.count,
1033                         (unsigned long long)hdr->args.offset);
1034
1035                 task->tk_status = pnfs_read_done_resend_to_mds(hdr);
1036         }
1037 }
1038
1039 static int ff_layout_async_handle_error_v4(struct rpc_task *task,
1040                                            struct nfs4_state *state,
1041                                            struct nfs_client *clp,
1042                                            struct pnfs_layout_segment *lseg,
1043                                            int idx)
1044 {
1045         struct pnfs_layout_hdr *lo = lseg->pls_layout;
1046         struct inode *inode = lo->plh_inode;
1047         struct nfs4_deviceid_node *devid = FF_LAYOUT_DEVID_NODE(lseg, idx);
1048         struct nfs4_slot_table *tbl = &clp->cl_session->fc_slot_table;
1049
1050         switch (task->tk_status) {
1051         case -NFS4ERR_BADSESSION:
1052         case -NFS4ERR_BADSLOT:
1053         case -NFS4ERR_BAD_HIGH_SLOT:
1054         case -NFS4ERR_DEADSESSION:
1055         case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1056         case -NFS4ERR_SEQ_FALSE_RETRY:
1057         case -NFS4ERR_SEQ_MISORDERED:
1058                 dprintk("%s ERROR %d, Reset session. Exchangeid "
1059                         "flags 0x%x\n", __func__, task->tk_status,
1060                         clp->cl_exchange_flags);
1061                 nfs4_schedule_session_recovery(clp->cl_session, task->tk_status);
1062                 break;
1063         case -NFS4ERR_DELAY:
1064         case -NFS4ERR_GRACE:
1065                 rpc_delay(task, FF_LAYOUT_POLL_RETRY_MAX);
1066                 break;
1067         case -NFS4ERR_RETRY_UNCACHED_REP:
1068                 break;
1069         /* Invalidate Layout errors */
1070         case -NFS4ERR_PNFS_NO_LAYOUT:
1071         case -ESTALE:           /* mapped NFS4ERR_STALE */
1072         case -EBADHANDLE:       /* mapped NFS4ERR_BADHANDLE */
1073         case -EISDIR:           /* mapped NFS4ERR_ISDIR */
1074         case -NFS4ERR_FHEXPIRED:
1075         case -NFS4ERR_WRONG_TYPE:
1076                 dprintk("%s Invalid layout error %d\n", __func__,
1077                         task->tk_status);
1078                 /*
1079                  * Destroy layout so new i/o will get a new layout.
1080                  * Layout will not be destroyed until all current lseg
1081                  * references are put. Mark layout as invalid to resend failed
1082                  * i/o and all i/o waiting on the slot table to the MDS until
1083                  * layout is destroyed and a new valid layout is obtained.
1084                  */
1085                 pnfs_destroy_layout(NFS_I(inode));
1086                 rpc_wake_up(&tbl->slot_tbl_waitq);
1087                 goto reset;
1088         /* RPC connection errors */
1089         case -ECONNREFUSED:
1090         case -EHOSTDOWN:
1091         case -EHOSTUNREACH:
1092         case -ENETUNREACH:
1093         case -EIO:
1094         case -ETIMEDOUT:
1095         case -EPIPE:
1096                 dprintk("%s DS connection error %d\n", __func__,
1097                         task->tk_status);
1098                 nfs4_delete_deviceid(devid->ld, devid->nfs_client,
1099                                 &devid->deviceid);
1100                 rpc_wake_up(&tbl->slot_tbl_waitq);
1101                 /* fall through */
1102         default:
1103                 if (ff_layout_avoid_mds_available_ds(lseg))
1104                         return -NFS4ERR_RESET_TO_PNFS;
1105 reset:
1106                 dprintk("%s Retry through MDS. Error %d\n", __func__,
1107                         task->tk_status);
1108                 return -NFS4ERR_RESET_TO_MDS;
1109         }
1110         task->tk_status = 0;
1111         return -EAGAIN;
1112 }
1113
1114 /* Retry all errors through either pNFS or MDS except for -EJUKEBOX */
1115 static int ff_layout_async_handle_error_v3(struct rpc_task *task,
1116                                            struct pnfs_layout_segment *lseg,
1117                                            int idx)
1118 {
1119         struct nfs4_deviceid_node *devid = FF_LAYOUT_DEVID_NODE(lseg, idx);
1120
1121         switch (task->tk_status) {
1122         /* File access problems. Don't mark the device as unavailable */
1123         case -EACCES:
1124         case -ESTALE:
1125         case -EISDIR:
1126         case -EBADHANDLE:
1127         case -ELOOP:
1128         case -ENOSPC:
1129                 break;
1130         case -EJUKEBOX:
1131                 nfs_inc_stats(lseg->pls_layout->plh_inode, NFSIOS_DELAY);
1132                 goto out_retry;
1133         default:
1134                 dprintk("%s DS connection error %d\n", __func__,
1135                         task->tk_status);
1136                 nfs4_delete_deviceid(devid->ld, devid->nfs_client,
1137                                 &devid->deviceid);
1138         }
1139         /* FIXME: Need to prevent infinite looping here. */
1140         return -NFS4ERR_RESET_TO_PNFS;
1141 out_retry:
1142         task->tk_status = 0;
1143         rpc_restart_call_prepare(task);
1144         rpc_delay(task, NFS_JUKEBOX_RETRY_TIME);
1145         return -EAGAIN;
1146 }
1147
1148 static int ff_layout_async_handle_error(struct rpc_task *task,
1149                                         struct nfs4_state *state,
1150                                         struct nfs_client *clp,
1151                                         struct pnfs_layout_segment *lseg,
1152                                         int idx)
1153 {
1154         int vers = clp->cl_nfs_mod->rpc_vers->number;
1155
1156         if (task->tk_status >= 0)
1157                 return 0;
1158
1159         /* Handle the case of an invalid layout segment */
1160         if (!pnfs_is_valid_lseg(lseg))
1161                 return -NFS4ERR_RESET_TO_PNFS;
1162
1163         switch (vers) {
1164         case 3:
1165                 return ff_layout_async_handle_error_v3(task, lseg, idx);
1166         case 4:
1167                 return ff_layout_async_handle_error_v4(task, state, clp,
1168                                                        lseg, idx);
1169         default:
1170                 /* should never happen */
1171                 WARN_ON_ONCE(1);
1172                 return 0;
1173         }
1174 }
1175
1176 static void ff_layout_io_track_ds_error(struct pnfs_layout_segment *lseg,
1177                                         int idx, u64 offset, u64 length,
1178                                         u32 status, int opnum, int error)
1179 {
1180         struct nfs4_ff_layout_mirror *mirror;
1181         int err;
1182
1183         if (status == 0) {
1184                 switch (error) {
1185                 case -ETIMEDOUT:
1186                 case -EPFNOSUPPORT:
1187                 case -EPROTONOSUPPORT:
1188                 case -EOPNOTSUPP:
1189                 case -ECONNREFUSED:
1190                 case -ECONNRESET:
1191                 case -EHOSTDOWN:
1192                 case -EHOSTUNREACH:
1193                 case -ENETUNREACH:
1194                 case -EADDRINUSE:
1195                 case -ENOBUFS:
1196                 case -EPIPE:
1197                 case -EPERM:
1198                         status = NFS4ERR_NXIO;
1199                         break;
1200                 case -EACCES:
1201                         status = NFS4ERR_ACCESS;
1202                         break;
1203                 default:
1204                         return;
1205                 }
1206         }
1207
1208         switch (status) {
1209         case NFS4ERR_DELAY:
1210         case NFS4ERR_GRACE:
1211                 return;
1212         default:
1213                 break;
1214         }
1215
1216         mirror = FF_LAYOUT_COMP(lseg, idx);
1217         err = ff_layout_track_ds_error(FF_LAYOUT_FROM_HDR(lseg->pls_layout),
1218                                        mirror, offset, length, status, opnum,
1219                                        GFP_NOIO);
1220         pnfs_error_mark_layout_for_return(lseg->pls_layout->plh_inode, lseg);
1221         dprintk("%s: err %d op %d status %u\n", __func__, err, opnum, status);
1222 }
1223
1224 /* NFS_PROTO call done callback routines */
1225 static int ff_layout_read_done_cb(struct rpc_task *task,
1226                                 struct nfs_pgio_header *hdr)
1227 {
1228         int err;
1229
1230         trace_nfs4_pnfs_read(hdr, task->tk_status);
1231         if (task->tk_status < 0)
1232                 ff_layout_io_track_ds_error(hdr->lseg, hdr->pgio_mirror_idx,
1233                                             hdr->args.offset, hdr->args.count,
1234                                             hdr->res.op_status, OP_READ,
1235                                             task->tk_status);
1236         err = ff_layout_async_handle_error(task, hdr->args.context->state,
1237                                            hdr->ds_clp, hdr->lseg,
1238                                            hdr->pgio_mirror_idx);
1239
1240         clear_bit(NFS_IOHDR_RESEND_PNFS, &hdr->flags);
1241         clear_bit(NFS_IOHDR_RESEND_MDS, &hdr->flags);
1242         switch (err) {
1243         case -NFS4ERR_RESET_TO_PNFS:
1244                 if (ff_layout_choose_best_ds_for_read(hdr->lseg,
1245                                         hdr->pgio_mirror_idx + 1,
1246                                         &hdr->pgio_mirror_idx))
1247                         goto out_eagain;
1248                 set_bit(NFS_IOHDR_RESEND_PNFS, &hdr->flags);
1249                 return task->tk_status;
1250         case -NFS4ERR_RESET_TO_MDS:
1251                 set_bit(NFS_IOHDR_RESEND_MDS, &hdr->flags);
1252                 return task->tk_status;
1253         case -EAGAIN:
1254                 goto out_eagain;
1255         }
1256
1257         return 0;
1258 out_eagain:
1259         rpc_restart_call_prepare(task);
1260         return -EAGAIN;
1261 }
1262
1263 static bool
1264 ff_layout_need_layoutcommit(struct pnfs_layout_segment *lseg)
1265 {
1266         return !(FF_LAYOUT_LSEG(lseg)->flags & FF_FLAGS_NO_LAYOUTCOMMIT);
1267 }
1268
1269 /*
1270  * We reference the rpc_cred of the first WRITE that triggers the need for
1271  * a LAYOUTCOMMIT, and use it to send the layoutcommit compound.
1272  * rfc5661 is not clear about which credential should be used.
1273  *
1274  * Flexlayout client should treat DS replied FILE_SYNC as DATA_SYNC, so
1275  * to follow http://www.rfc-editor.org/errata_search.php?rfc=5661&eid=2751
1276  * we always send layoutcommit after DS writes.
1277  */
1278 static void
1279 ff_layout_set_layoutcommit(struct inode *inode,
1280                 struct pnfs_layout_segment *lseg,
1281                 loff_t end_offset)
1282 {
1283         if (!ff_layout_need_layoutcommit(lseg))
1284                 return;
1285
1286         pnfs_set_layoutcommit(inode, lseg, end_offset);
1287         dprintk("%s inode %lu pls_end_pos %llu\n", __func__, inode->i_ino,
1288                 (unsigned long long) NFS_I(inode)->layout->plh_lwb);
1289 }
1290
1291 static bool
1292 ff_layout_device_unavailable(struct pnfs_layout_segment *lseg, int idx)
1293 {
1294         /* No mirroring for now */
1295         struct nfs4_deviceid_node *node = FF_LAYOUT_DEVID_NODE(lseg, idx);
1296
1297         return ff_layout_test_devid_unavailable(node);
1298 }
1299
1300 static void ff_layout_read_record_layoutstats_start(struct rpc_task *task,
1301                 struct nfs_pgio_header *hdr)
1302 {
1303         if (test_and_set_bit(NFS_IOHDR_STAT, &hdr->flags))
1304                 return;
1305         nfs4_ff_layout_stat_io_start_read(hdr->inode,
1306                         FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
1307                         hdr->args.count,
1308                         task->tk_start);
1309 }
1310
1311 static void ff_layout_read_record_layoutstats_done(struct rpc_task *task,
1312                 struct nfs_pgio_header *hdr)
1313 {
1314         if (!test_and_clear_bit(NFS_IOHDR_STAT, &hdr->flags))
1315                 return;
1316         nfs4_ff_layout_stat_io_end_read(task,
1317                         FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
1318                         hdr->args.count,
1319                         hdr->res.count);
1320         set_bit(NFS_LSEG_LAYOUTRETURN, &hdr->lseg->pls_flags);
1321 }
1322
1323 static int ff_layout_read_prepare_common(struct rpc_task *task,
1324                                          struct nfs_pgio_header *hdr)
1325 {
1326         if (unlikely(test_bit(NFS_CONTEXT_BAD, &hdr->args.context->flags))) {
1327                 rpc_exit(task, -EIO);
1328                 return -EIO;
1329         }
1330         if (ff_layout_device_unavailable(hdr->lseg, hdr->pgio_mirror_idx)) {
1331                 rpc_exit(task, -EHOSTDOWN);
1332                 return -EAGAIN;
1333         }
1334
1335         ff_layout_read_record_layoutstats_start(task, hdr);
1336         return 0;
1337 }
1338
1339 /*
1340  * Call ops for the async read/write cases
1341  * In the case of dense layouts, the offset needs to be reset to its
1342  * original value.
1343  */
1344 static void ff_layout_read_prepare_v3(struct rpc_task *task, void *data)
1345 {
1346         struct nfs_pgio_header *hdr = data;
1347
1348         if (ff_layout_read_prepare_common(task, hdr))
1349                 return;
1350
1351         rpc_call_start(task);
1352 }
1353
1354 static void ff_layout_read_prepare_v4(struct rpc_task *task, void *data)
1355 {
1356         struct nfs_pgio_header *hdr = data;
1357
1358         if (nfs4_setup_sequence(hdr->ds_clp,
1359                                 &hdr->args.seq_args,
1360                                 &hdr->res.seq_res,
1361                                 task))
1362                 return;
1363
1364         if (ff_layout_read_prepare_common(task, hdr))
1365                 return;
1366
1367         if (nfs4_set_rw_stateid(&hdr->args.stateid, hdr->args.context,
1368                         hdr->args.lock_context, FMODE_READ) == -EIO)
1369                 rpc_exit(task, -EIO); /* lost lock, terminate I/O */
1370 }
1371
1372 static void ff_layout_read_call_done(struct rpc_task *task, void *data)
1373 {
1374         struct nfs_pgio_header *hdr = data;
1375
1376         dprintk("--> %s task->tk_status %d\n", __func__, task->tk_status);
1377
1378         if (test_bit(NFS_IOHDR_REDO, &hdr->flags) &&
1379             task->tk_status == 0) {
1380                 nfs4_sequence_done(task, &hdr->res.seq_res);
1381                 return;
1382         }
1383
1384         /* Note this may cause RPC to be resent */
1385         hdr->mds_ops->rpc_call_done(task, hdr);
1386 }
1387
1388 static void ff_layout_read_count_stats(struct rpc_task *task, void *data)
1389 {
1390         struct nfs_pgio_header *hdr = data;
1391
1392         ff_layout_read_record_layoutstats_done(task, hdr);
1393         rpc_count_iostats_metrics(task,
1394             &NFS_CLIENT(hdr->inode)->cl_metrics[NFSPROC4_CLNT_READ]);
1395 }
1396
1397 static void ff_layout_read_release(void *data)
1398 {
1399         struct nfs_pgio_header *hdr = data;
1400
1401         ff_layout_read_record_layoutstats_done(&hdr->task, hdr);
1402         if (test_bit(NFS_IOHDR_RESEND_PNFS, &hdr->flags))
1403                 pnfs_read_resend_pnfs(hdr);
1404         else if (test_bit(NFS_IOHDR_RESEND_MDS, &hdr->flags))
1405                 ff_layout_reset_read(hdr);
1406         pnfs_generic_rw_release(data);
1407 }
1408
1409
1410 static int ff_layout_write_done_cb(struct rpc_task *task,
1411                                 struct nfs_pgio_header *hdr)
1412 {
1413         loff_t end_offs = 0;
1414         int err;
1415
1416         trace_nfs4_pnfs_write(hdr, task->tk_status);
1417         if (task->tk_status < 0)
1418                 ff_layout_io_track_ds_error(hdr->lseg, hdr->pgio_mirror_idx,
1419                                             hdr->args.offset, hdr->args.count,
1420                                             hdr->res.op_status, OP_WRITE,
1421                                             task->tk_status);
1422         err = ff_layout_async_handle_error(task, hdr->args.context->state,
1423                                            hdr->ds_clp, hdr->lseg,
1424                                            hdr->pgio_mirror_idx);
1425
1426         clear_bit(NFS_IOHDR_RESEND_PNFS, &hdr->flags);
1427         clear_bit(NFS_IOHDR_RESEND_MDS, &hdr->flags);
1428         switch (err) {
1429         case -NFS4ERR_RESET_TO_PNFS:
1430                 set_bit(NFS_IOHDR_RESEND_PNFS, &hdr->flags);
1431                 return task->tk_status;
1432         case -NFS4ERR_RESET_TO_MDS:
1433                 set_bit(NFS_IOHDR_RESEND_MDS, &hdr->flags);
1434                 return task->tk_status;
1435         case -EAGAIN:
1436                 return -EAGAIN;
1437         }
1438
1439         if (hdr->res.verf->committed == NFS_FILE_SYNC ||
1440             hdr->res.verf->committed == NFS_DATA_SYNC)
1441                 end_offs = hdr->mds_offset + (loff_t)hdr->res.count;
1442
1443         /* Note: if the write is unstable, don't set end_offs until commit */
1444         ff_layout_set_layoutcommit(hdr->inode, hdr->lseg, end_offs);
1445
1446         /* zero out fattr since we don't care DS attr at all */
1447         hdr->fattr.valid = 0;
1448         if (task->tk_status >= 0)
1449                 nfs_writeback_update_inode(hdr);
1450
1451         return 0;
1452 }
1453
1454 static int ff_layout_commit_done_cb(struct rpc_task *task,
1455                                      struct nfs_commit_data *data)
1456 {
1457         int err;
1458
1459         trace_nfs4_pnfs_commit_ds(data, task->tk_status);
1460         if (task->tk_status < 0)
1461                 ff_layout_io_track_ds_error(data->lseg, data->ds_commit_index,
1462                                             data->args.offset, data->args.count,
1463                                             data->res.op_status, OP_COMMIT,
1464                                             task->tk_status);
1465         err = ff_layout_async_handle_error(task, NULL, data->ds_clp,
1466                                            data->lseg, data->ds_commit_index);
1467
1468         switch (err) {
1469         case -NFS4ERR_RESET_TO_PNFS:
1470                 pnfs_generic_prepare_to_resend_writes(data);
1471                 return -EAGAIN;
1472         case -NFS4ERR_RESET_TO_MDS:
1473                 pnfs_generic_prepare_to_resend_writes(data);
1474                 return -EAGAIN;
1475         case -EAGAIN:
1476                 rpc_restart_call_prepare(task);
1477                 return -EAGAIN;
1478         }
1479
1480         ff_layout_set_layoutcommit(data->inode, data->lseg, data->lwb);
1481
1482         return 0;
1483 }
1484
1485 static void ff_layout_write_record_layoutstats_start(struct rpc_task *task,
1486                 struct nfs_pgio_header *hdr)
1487 {
1488         if (test_and_set_bit(NFS_IOHDR_STAT, &hdr->flags))
1489                 return;
1490         nfs4_ff_layout_stat_io_start_write(hdr->inode,
1491                         FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
1492                         hdr->args.count,
1493                         task->tk_start);
1494 }
1495
1496 static void ff_layout_write_record_layoutstats_done(struct rpc_task *task,
1497                 struct nfs_pgio_header *hdr)
1498 {
1499         if (!test_and_clear_bit(NFS_IOHDR_STAT, &hdr->flags))
1500                 return;
1501         nfs4_ff_layout_stat_io_end_write(task,
1502                         FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
1503                         hdr->args.count, hdr->res.count,
1504                         hdr->res.verf->committed);
1505         set_bit(NFS_LSEG_LAYOUTRETURN, &hdr->lseg->pls_flags);
1506 }
1507
1508 static int ff_layout_write_prepare_common(struct rpc_task *task,
1509                                           struct nfs_pgio_header *hdr)
1510 {
1511         if (unlikely(test_bit(NFS_CONTEXT_BAD, &hdr->args.context->flags))) {
1512                 rpc_exit(task, -EIO);
1513                 return -EIO;
1514         }
1515
1516         if (ff_layout_device_unavailable(hdr->lseg, hdr->pgio_mirror_idx)) {
1517                 rpc_exit(task, -EHOSTDOWN);
1518                 return -EAGAIN;
1519         }
1520
1521         ff_layout_write_record_layoutstats_start(task, hdr);
1522         return 0;
1523 }
1524
1525 static void ff_layout_write_prepare_v3(struct rpc_task *task, void *data)
1526 {
1527         struct nfs_pgio_header *hdr = data;
1528
1529         if (ff_layout_write_prepare_common(task, hdr))
1530                 return;
1531
1532         rpc_call_start(task);
1533 }
1534
1535 static void ff_layout_write_prepare_v4(struct rpc_task *task, void *data)
1536 {
1537         struct nfs_pgio_header *hdr = data;
1538
1539         if (nfs4_setup_sequence(hdr->ds_clp,
1540                                 &hdr->args.seq_args,
1541                                 &hdr->res.seq_res,
1542                                 task))
1543                 return;
1544
1545         if (ff_layout_write_prepare_common(task, hdr))
1546                 return;
1547
1548         if (nfs4_set_rw_stateid(&hdr->args.stateid, hdr->args.context,
1549                         hdr->args.lock_context, FMODE_WRITE) == -EIO)
1550                 rpc_exit(task, -EIO); /* lost lock, terminate I/O */
1551 }
1552
1553 static void ff_layout_write_call_done(struct rpc_task *task, void *data)
1554 {
1555         struct nfs_pgio_header *hdr = data;
1556
1557         if (test_bit(NFS_IOHDR_REDO, &hdr->flags) &&
1558             task->tk_status == 0) {
1559                 nfs4_sequence_done(task, &hdr->res.seq_res);
1560                 return;
1561         }
1562
1563         /* Note this may cause RPC to be resent */
1564         hdr->mds_ops->rpc_call_done(task, hdr);
1565 }
1566
1567 static void ff_layout_write_count_stats(struct rpc_task *task, void *data)
1568 {
1569         struct nfs_pgio_header *hdr = data;
1570
1571         ff_layout_write_record_layoutstats_done(task, hdr);
1572         rpc_count_iostats_metrics(task,
1573             &NFS_CLIENT(hdr->inode)->cl_metrics[NFSPROC4_CLNT_WRITE]);
1574 }
1575
1576 static void ff_layout_write_release(void *data)
1577 {
1578         struct nfs_pgio_header *hdr = data;
1579
1580         ff_layout_write_record_layoutstats_done(&hdr->task, hdr);
1581         if (test_bit(NFS_IOHDR_RESEND_PNFS, &hdr->flags))
1582                 ff_layout_reset_write(hdr, true);
1583         else if (test_bit(NFS_IOHDR_RESEND_MDS, &hdr->flags))
1584                 ff_layout_reset_write(hdr, false);
1585         pnfs_generic_rw_release(data);
1586 }
1587
1588 static void ff_layout_commit_record_layoutstats_start(struct rpc_task *task,
1589                 struct nfs_commit_data *cdata)
1590 {
1591         if (test_and_set_bit(NFS_IOHDR_STAT, &cdata->flags))
1592                 return;
1593         nfs4_ff_layout_stat_io_start_write(cdata->inode,
1594                         FF_LAYOUT_COMP(cdata->lseg, cdata->ds_commit_index),
1595                         0, task->tk_start);
1596 }
1597
1598 static void ff_layout_commit_record_layoutstats_done(struct rpc_task *task,
1599                 struct nfs_commit_data *cdata)
1600 {
1601         struct nfs_page *req;
1602         __u64 count = 0;
1603
1604         if (!test_and_clear_bit(NFS_IOHDR_STAT, &cdata->flags))
1605                 return;
1606
1607         if (task->tk_status == 0) {
1608                 list_for_each_entry(req, &cdata->pages, wb_list)
1609                         count += req->wb_bytes;
1610         }
1611         nfs4_ff_layout_stat_io_end_write(task,
1612                         FF_LAYOUT_COMP(cdata->lseg, cdata->ds_commit_index),
1613                         count, count, NFS_FILE_SYNC);
1614         set_bit(NFS_LSEG_LAYOUTRETURN, &cdata->lseg->pls_flags);
1615 }
1616
1617 static void ff_layout_commit_prepare_common(struct rpc_task *task,
1618                 struct nfs_commit_data *cdata)
1619 {
1620         ff_layout_commit_record_layoutstats_start(task, cdata);
1621 }
1622
1623 static void ff_layout_commit_prepare_v3(struct rpc_task *task, void *data)
1624 {
1625         ff_layout_commit_prepare_common(task, data);
1626         rpc_call_start(task);
1627 }
1628
1629 static void ff_layout_commit_prepare_v4(struct rpc_task *task, void *data)
1630 {
1631         struct nfs_commit_data *wdata = data;
1632
1633         if (nfs4_setup_sequence(wdata->ds_clp,
1634                                 &wdata->args.seq_args,
1635                                 &wdata->res.seq_res,
1636                                 task))
1637                 return;
1638         ff_layout_commit_prepare_common(task, data);
1639 }
1640
1641 static void ff_layout_commit_done(struct rpc_task *task, void *data)
1642 {
1643         pnfs_generic_write_commit_done(task, data);
1644 }
1645
1646 static void ff_layout_commit_count_stats(struct rpc_task *task, void *data)
1647 {
1648         struct nfs_commit_data *cdata = data;
1649
1650         ff_layout_commit_record_layoutstats_done(task, cdata);
1651         rpc_count_iostats_metrics(task,
1652             &NFS_CLIENT(cdata->inode)->cl_metrics[NFSPROC4_CLNT_COMMIT]);
1653 }
1654
1655 static void ff_layout_commit_release(void *data)
1656 {
1657         struct nfs_commit_data *cdata = data;
1658
1659         ff_layout_commit_record_layoutstats_done(&cdata->task, cdata);
1660         pnfs_generic_commit_release(data);
1661 }
1662
1663 static const struct rpc_call_ops ff_layout_read_call_ops_v3 = {
1664         .rpc_call_prepare = ff_layout_read_prepare_v3,
1665         .rpc_call_done = ff_layout_read_call_done,
1666         .rpc_count_stats = ff_layout_read_count_stats,
1667         .rpc_release = ff_layout_read_release,
1668 };
1669
1670 static const struct rpc_call_ops ff_layout_read_call_ops_v4 = {
1671         .rpc_call_prepare = ff_layout_read_prepare_v4,
1672         .rpc_call_done = ff_layout_read_call_done,
1673         .rpc_count_stats = ff_layout_read_count_stats,
1674         .rpc_release = ff_layout_read_release,
1675 };
1676
1677 static const struct rpc_call_ops ff_layout_write_call_ops_v3 = {
1678         .rpc_call_prepare = ff_layout_write_prepare_v3,
1679         .rpc_call_done = ff_layout_write_call_done,
1680         .rpc_count_stats = ff_layout_write_count_stats,
1681         .rpc_release = ff_layout_write_release,
1682 };
1683
1684 static const struct rpc_call_ops ff_layout_write_call_ops_v4 = {
1685         .rpc_call_prepare = ff_layout_write_prepare_v4,
1686         .rpc_call_done = ff_layout_write_call_done,
1687         .rpc_count_stats = ff_layout_write_count_stats,
1688         .rpc_release = ff_layout_write_release,
1689 };
1690
1691 static const struct rpc_call_ops ff_layout_commit_call_ops_v3 = {
1692         .rpc_call_prepare = ff_layout_commit_prepare_v3,
1693         .rpc_call_done = ff_layout_commit_done,
1694         .rpc_count_stats = ff_layout_commit_count_stats,
1695         .rpc_release = ff_layout_commit_release,
1696 };
1697
1698 static const struct rpc_call_ops ff_layout_commit_call_ops_v4 = {
1699         .rpc_call_prepare = ff_layout_commit_prepare_v4,
1700         .rpc_call_done = ff_layout_commit_done,
1701         .rpc_count_stats = ff_layout_commit_count_stats,
1702         .rpc_release = ff_layout_commit_release,
1703 };
1704
1705 static enum pnfs_try_status
1706 ff_layout_read_pagelist(struct nfs_pgio_header *hdr)
1707 {
1708         struct pnfs_layout_segment *lseg = hdr->lseg;
1709         struct nfs4_pnfs_ds *ds;
1710         struct rpc_clnt *ds_clnt;
1711         struct rpc_cred *ds_cred;
1712         loff_t offset = hdr->args.offset;
1713         u32 idx = hdr->pgio_mirror_idx;
1714         int vers;
1715         struct nfs_fh *fh;
1716
1717         dprintk("--> %s ino %lu pgbase %u req %zu@%llu\n",
1718                 __func__, hdr->inode->i_ino,
1719                 hdr->args.pgbase, (size_t)hdr->args.count, offset);
1720
1721         ds = nfs4_ff_layout_prepare_ds(lseg, idx, false);
1722         if (!ds)
1723                 goto out_failed;
1724
1725         ds_clnt = nfs4_ff_find_or_create_ds_client(lseg, idx, ds->ds_clp,
1726                                                    hdr->inode);
1727         if (IS_ERR(ds_clnt))
1728                 goto out_failed;
1729
1730         ds_cred = ff_layout_get_ds_cred(lseg, idx, hdr->cred);
1731         if (!ds_cred)
1732                 goto out_failed;
1733
1734         vers = nfs4_ff_layout_ds_version(lseg, idx);
1735
1736         dprintk("%s USE DS: %s cl_count %d vers %d\n", __func__,
1737                 ds->ds_remotestr, refcount_read(&ds->ds_clp->cl_count), vers);
1738
1739         hdr->pgio_done_cb = ff_layout_read_done_cb;
1740         refcount_inc(&ds->ds_clp->cl_count);
1741         hdr->ds_clp = ds->ds_clp;
1742         fh = nfs4_ff_layout_select_ds_fh(lseg, idx);
1743         if (fh)
1744                 hdr->args.fh = fh;
1745         /*
1746          * Note that if we ever decide to split across DSes,
1747          * then we may need to handle dense-like offsets.
1748          */
1749         hdr->args.offset = offset;
1750         hdr->mds_offset = offset;
1751
1752         /* Perform an asynchronous read to ds */
1753         nfs_initiate_pgio(ds_clnt, hdr, ds_cred, ds->ds_clp->rpc_ops,
1754                           vers == 3 ? &ff_layout_read_call_ops_v3 :
1755                                       &ff_layout_read_call_ops_v4,
1756                           0, RPC_TASK_SOFTCONN);
1757         put_rpccred(ds_cred);
1758         return PNFS_ATTEMPTED;
1759
1760 out_failed:
1761         if (ff_layout_avoid_mds_available_ds(lseg))
1762                 return PNFS_TRY_AGAIN;
1763         return PNFS_NOT_ATTEMPTED;
1764 }
1765
1766 /* Perform async writes. */
1767 static enum pnfs_try_status
1768 ff_layout_write_pagelist(struct nfs_pgio_header *hdr, int sync)
1769 {
1770         struct pnfs_layout_segment *lseg = hdr->lseg;
1771         struct nfs4_pnfs_ds *ds;
1772         struct rpc_clnt *ds_clnt;
1773         struct rpc_cred *ds_cred;
1774         loff_t offset = hdr->args.offset;
1775         int vers;
1776         struct nfs_fh *fh;
1777         int idx = hdr->pgio_mirror_idx;
1778
1779         ds = nfs4_ff_layout_prepare_ds(lseg, idx, true);
1780         if (!ds)
1781                 goto out_failed;
1782
1783         ds_clnt = nfs4_ff_find_or_create_ds_client(lseg, idx, ds->ds_clp,
1784                                                    hdr->inode);
1785         if (IS_ERR(ds_clnt))
1786                 goto out_failed;
1787
1788         ds_cred = ff_layout_get_ds_cred(lseg, idx, hdr->cred);
1789         if (!ds_cred)
1790                 goto out_failed;
1791
1792         vers = nfs4_ff_layout_ds_version(lseg, idx);
1793
1794         dprintk("%s ino %lu sync %d req %zu@%llu DS: %s cl_count %d vers %d\n",
1795                 __func__, hdr->inode->i_ino, sync, (size_t) hdr->args.count,
1796                 offset, ds->ds_remotestr, refcount_read(&ds->ds_clp->cl_count),
1797                 vers);
1798
1799         hdr->pgio_done_cb = ff_layout_write_done_cb;
1800         refcount_inc(&ds->ds_clp->cl_count);
1801         hdr->ds_clp = ds->ds_clp;
1802         hdr->ds_commit_idx = idx;
1803         fh = nfs4_ff_layout_select_ds_fh(lseg, idx);
1804         if (fh)
1805                 hdr->args.fh = fh;
1806
1807         /*
1808          * Note that if we ever decide to split across DSes,
1809          * then we may need to handle dense-like offsets.
1810          */
1811         hdr->args.offset = offset;
1812
1813         /* Perform an asynchronous write */
1814         nfs_initiate_pgio(ds_clnt, hdr, ds_cred, ds->ds_clp->rpc_ops,
1815                           vers == 3 ? &ff_layout_write_call_ops_v3 :
1816                                       &ff_layout_write_call_ops_v4,
1817                           sync, RPC_TASK_SOFTCONN);
1818         put_rpccred(ds_cred);
1819         return PNFS_ATTEMPTED;
1820
1821 out_failed:
1822         if (ff_layout_avoid_mds_available_ds(lseg))
1823                 return PNFS_TRY_AGAIN;
1824         return PNFS_NOT_ATTEMPTED;
1825 }
1826
1827 static u32 calc_ds_index_from_commit(struct pnfs_layout_segment *lseg, u32 i)
1828 {
1829         return i;
1830 }
1831
1832 static struct nfs_fh *
1833 select_ds_fh_from_commit(struct pnfs_layout_segment *lseg, u32 i)
1834 {
1835         struct nfs4_ff_layout_segment *flseg = FF_LAYOUT_LSEG(lseg);
1836
1837         /* FIXME: Assume that there is only one NFS version available
1838          * for the DS.
1839          */
1840         return &flseg->mirror_array[i]->fh_versions[0];
1841 }
1842
1843 static int ff_layout_initiate_commit(struct nfs_commit_data *data, int how)
1844 {
1845         struct pnfs_layout_segment *lseg = data->lseg;
1846         struct nfs4_pnfs_ds *ds;
1847         struct rpc_clnt *ds_clnt;
1848         struct rpc_cred *ds_cred;
1849         u32 idx;
1850         int vers, ret;
1851         struct nfs_fh *fh;
1852
1853         if (!lseg || !(pnfs_is_valid_lseg(lseg) ||
1854             test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags)))
1855                 goto out_err;
1856
1857         idx = calc_ds_index_from_commit(lseg, data->ds_commit_index);
1858         ds = nfs4_ff_layout_prepare_ds(lseg, idx, true);
1859         if (!ds)
1860                 goto out_err;
1861
1862         ds_clnt = nfs4_ff_find_or_create_ds_client(lseg, idx, ds->ds_clp,
1863                                                    data->inode);
1864         if (IS_ERR(ds_clnt))
1865                 goto out_err;
1866
1867         ds_cred = ff_layout_get_ds_cred(lseg, idx, data->cred);
1868         if (!ds_cred)
1869                 goto out_err;
1870
1871         vers = nfs4_ff_layout_ds_version(lseg, idx);
1872
1873         dprintk("%s ino %lu, how %d cl_count %d vers %d\n", __func__,
1874                 data->inode->i_ino, how, refcount_read(&ds->ds_clp->cl_count),
1875                 vers);
1876         data->commit_done_cb = ff_layout_commit_done_cb;
1877         data->cred = ds_cred;
1878         refcount_inc(&ds->ds_clp->cl_count);
1879         data->ds_clp = ds->ds_clp;
1880         fh = select_ds_fh_from_commit(lseg, data->ds_commit_index);
1881         if (fh)
1882                 data->args.fh = fh;
1883
1884         ret = nfs_initiate_commit(ds_clnt, data, ds->ds_clp->rpc_ops,
1885                                    vers == 3 ? &ff_layout_commit_call_ops_v3 :
1886                                                &ff_layout_commit_call_ops_v4,
1887                                    how, RPC_TASK_SOFTCONN);
1888         put_rpccred(ds_cred);
1889         return ret;
1890 out_err:
1891         pnfs_generic_prepare_to_resend_writes(data);
1892         pnfs_generic_commit_release(data);
1893         return -EAGAIN;
1894 }
1895
1896 static int
1897 ff_layout_commit_pagelist(struct inode *inode, struct list_head *mds_pages,
1898                            int how, struct nfs_commit_info *cinfo)
1899 {
1900         return pnfs_generic_commit_pagelist(inode, mds_pages, how, cinfo,
1901                                             ff_layout_initiate_commit);
1902 }
1903
1904 static struct pnfs_ds_commit_info *
1905 ff_layout_get_ds_info(struct inode *inode)
1906 {
1907         struct pnfs_layout_hdr *layout = NFS_I(inode)->layout;
1908
1909         if (layout == NULL)
1910                 return NULL;
1911
1912         return &FF_LAYOUT_FROM_HDR(layout)->commit_info;
1913 }
1914
1915 static void
1916 ff_layout_free_deviceid_node(struct nfs4_deviceid_node *d)
1917 {
1918         nfs4_ff_layout_free_deviceid(container_of(d, struct nfs4_ff_layout_ds,
1919                                                   id_node));
1920 }
1921
1922 static int ff_layout_encode_ioerr(struct xdr_stream *xdr,
1923                                   const struct nfs4_layoutreturn_args *args,
1924                                   const struct nfs4_flexfile_layoutreturn_args *ff_args)
1925 {
1926         __be32 *start;
1927
1928         start = xdr_reserve_space(xdr, 4);
1929         if (unlikely(!start))
1930                 return -E2BIG;
1931
1932         *start = cpu_to_be32(ff_args->num_errors);
1933         /* This assume we always return _ALL_ layouts */
1934         return ff_layout_encode_ds_ioerr(xdr, &ff_args->errors);
1935 }
1936
1937 static void
1938 encode_opaque_fixed(struct xdr_stream *xdr, const void *buf, size_t len)
1939 {
1940         WARN_ON_ONCE(xdr_stream_encode_opaque_fixed(xdr, buf, len) < 0);
1941 }
1942
1943 static void
1944 ff_layout_encode_ff_iostat_head(struct xdr_stream *xdr,
1945                             const nfs4_stateid *stateid,
1946                             const struct nfs42_layoutstat_devinfo *devinfo)
1947 {
1948         __be32 *p;
1949
1950         p = xdr_reserve_space(xdr, 8 + 8);
1951         p = xdr_encode_hyper(p, devinfo->offset);
1952         p = xdr_encode_hyper(p, devinfo->length);
1953         encode_opaque_fixed(xdr, stateid->data, NFS4_STATEID_SIZE);
1954         p = xdr_reserve_space(xdr, 4*8);
1955         p = xdr_encode_hyper(p, devinfo->read_count);
1956         p = xdr_encode_hyper(p, devinfo->read_bytes);
1957         p = xdr_encode_hyper(p, devinfo->write_count);
1958         p = xdr_encode_hyper(p, devinfo->write_bytes);
1959         encode_opaque_fixed(xdr, devinfo->dev_id.data, NFS4_DEVICEID4_SIZE);
1960 }
1961
1962 static void
1963 ff_layout_encode_ff_iostat(struct xdr_stream *xdr,
1964                             const nfs4_stateid *stateid,
1965                             const struct nfs42_layoutstat_devinfo *devinfo)
1966 {
1967         ff_layout_encode_ff_iostat_head(xdr, stateid, devinfo);
1968         ff_layout_encode_ff_layoutupdate(xdr, devinfo,
1969                         devinfo->ld_private.data);
1970 }
1971
1972 /* report nothing for now */
1973 static void ff_layout_encode_iostats_array(struct xdr_stream *xdr,
1974                 const struct nfs4_layoutreturn_args *args,
1975                 struct nfs4_flexfile_layoutreturn_args *ff_args)
1976 {
1977         __be32 *p;
1978         int i;
1979
1980         p = xdr_reserve_space(xdr, 4);
1981         *p = cpu_to_be32(ff_args->num_dev);
1982         for (i = 0; i < ff_args->num_dev; i++)
1983                 ff_layout_encode_ff_iostat(xdr,
1984                                 &args->layout->plh_stateid,
1985                                 &ff_args->devinfo[i]);
1986 }
1987
1988 static void
1989 ff_layout_free_iostats_array(struct nfs42_layoutstat_devinfo *devinfo,
1990                 unsigned int num_entries)
1991 {
1992         unsigned int i;
1993
1994         for (i = 0; i < num_entries; i++) {
1995                 if (!devinfo[i].ld_private.ops)
1996                         continue;
1997                 if (!devinfo[i].ld_private.ops->free)
1998                         continue;
1999                 devinfo[i].ld_private.ops->free(&devinfo[i].ld_private);
2000         }
2001 }
2002
2003 static struct nfs4_deviceid_node *
2004 ff_layout_alloc_deviceid_node(struct nfs_server *server,
2005                               struct pnfs_device *pdev, gfp_t gfp_flags)
2006 {
2007         struct nfs4_ff_layout_ds *dsaddr;
2008
2009         dsaddr = nfs4_ff_alloc_deviceid_node(server, pdev, gfp_flags);
2010         if (!dsaddr)
2011                 return NULL;
2012         return &dsaddr->id_node;
2013 }
2014
2015 static void
2016 ff_layout_encode_layoutreturn(struct xdr_stream *xdr,
2017                 const void *voidargs,
2018                 const struct nfs4_xdr_opaque_data *ff_opaque)
2019 {
2020         const struct nfs4_layoutreturn_args *args = voidargs;
2021         struct nfs4_flexfile_layoutreturn_args *ff_args = ff_opaque->data;
2022         struct xdr_buf tmp_buf = {
2023                 .head = {
2024                         [0] = {
2025                                 .iov_base = page_address(ff_args->pages[0]),
2026                         },
2027                 },
2028                 .buflen = PAGE_SIZE,
2029         };
2030         struct xdr_stream tmp_xdr;
2031         __be32 *start;
2032
2033         dprintk("%s: Begin\n", __func__);
2034
2035         xdr_init_encode(&tmp_xdr, &tmp_buf, NULL);
2036
2037         ff_layout_encode_ioerr(&tmp_xdr, args, ff_args);
2038         ff_layout_encode_iostats_array(&tmp_xdr, args, ff_args);
2039
2040         start = xdr_reserve_space(xdr, 4);
2041         *start = cpu_to_be32(tmp_buf.len);
2042         xdr_write_pages(xdr, ff_args->pages, 0, tmp_buf.len);
2043
2044         dprintk("%s: Return\n", __func__);
2045 }
2046
2047 static void
2048 ff_layout_free_layoutreturn(struct nfs4_xdr_opaque_data *args)
2049 {
2050         struct nfs4_flexfile_layoutreturn_args *ff_args;
2051
2052         if (!args->data)
2053                 return;
2054         ff_args = args->data;
2055         args->data = NULL;
2056
2057         ff_layout_free_ds_ioerr(&ff_args->errors);
2058         ff_layout_free_iostats_array(ff_args->devinfo, ff_args->num_dev);
2059
2060         put_page(ff_args->pages[0]);
2061         kfree(ff_args);
2062 }
2063
2064 static const struct nfs4_xdr_opaque_ops layoutreturn_ops = {
2065         .encode = ff_layout_encode_layoutreturn,
2066         .free = ff_layout_free_layoutreturn,
2067 };
2068
2069 static int
2070 ff_layout_prepare_layoutreturn(struct nfs4_layoutreturn_args *args)
2071 {
2072         struct nfs4_flexfile_layoutreturn_args *ff_args;
2073         struct nfs4_flexfile_layout *ff_layout = FF_LAYOUT_FROM_HDR(args->layout);
2074
2075         ff_args = kmalloc(sizeof(*ff_args), GFP_KERNEL);
2076         if (!ff_args)
2077                 goto out_nomem;
2078         ff_args->pages[0] = alloc_page(GFP_KERNEL);
2079         if (!ff_args->pages[0])
2080                 goto out_nomem_free;
2081
2082         INIT_LIST_HEAD(&ff_args->errors);
2083         ff_args->num_errors = ff_layout_fetch_ds_ioerr(args->layout,
2084                         &args->range, &ff_args->errors,
2085                         FF_LAYOUTRETURN_MAXERR);
2086
2087         spin_lock(&args->inode->i_lock);
2088         ff_args->num_dev = ff_layout_mirror_prepare_stats(&ff_layout->generic_hdr,
2089                         &ff_args->devinfo[0], ARRAY_SIZE(ff_args->devinfo));
2090         spin_unlock(&args->inode->i_lock);
2091
2092         args->ld_private->ops = &layoutreturn_ops;
2093         args->ld_private->data = ff_args;
2094         return 0;
2095 out_nomem_free:
2096         kfree(ff_args);
2097 out_nomem:
2098         return -ENOMEM;
2099 }
2100
2101 static int
2102 ff_layout_ntop4(const struct sockaddr *sap, char *buf, const size_t buflen)
2103 {
2104         const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
2105
2106         return snprintf(buf, buflen, "%pI4", &sin->sin_addr);
2107 }
2108
2109 static size_t
2110 ff_layout_ntop6_noscopeid(const struct sockaddr *sap, char *buf,
2111                           const int buflen)
2112 {
2113         const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
2114         const struct in6_addr *addr = &sin6->sin6_addr;
2115
2116         /*
2117          * RFC 4291, Section 2.2.2
2118          *
2119          * Shorthanded ANY address
2120          */
2121         if (ipv6_addr_any(addr))
2122                 return snprintf(buf, buflen, "::");
2123
2124         /*
2125          * RFC 4291, Section 2.2.2
2126          *
2127          * Shorthanded loopback address
2128          */
2129         if (ipv6_addr_loopback(addr))
2130                 return snprintf(buf, buflen, "::1");
2131
2132         /*
2133          * RFC 4291, Section 2.2.3
2134          *
2135          * Special presentation address format for mapped v4
2136          * addresses.
2137          */
2138         if (ipv6_addr_v4mapped(addr))
2139                 return snprintf(buf, buflen, "::ffff:%pI4",
2140                                         &addr->s6_addr32[3]);
2141
2142         /*
2143          * RFC 4291, Section 2.2.1
2144          */
2145         return snprintf(buf, buflen, "%pI6c", addr);
2146 }
2147
2148 /* Derived from rpc_sockaddr2uaddr */
2149 static void
2150 ff_layout_encode_netaddr(struct xdr_stream *xdr, struct nfs4_pnfs_ds_addr *da)
2151 {
2152         struct sockaddr *sap = (struct sockaddr *)&da->da_addr;
2153         char portbuf[RPCBIND_MAXUADDRPLEN];
2154         char addrbuf[RPCBIND_MAXUADDRLEN];
2155         char *netid;
2156         unsigned short port;
2157         int len, netid_len;
2158         __be32 *p;
2159
2160         switch (sap->sa_family) {
2161         case AF_INET:
2162                 if (ff_layout_ntop4(sap, addrbuf, sizeof(addrbuf)) == 0)
2163                         return;
2164                 port = ntohs(((struct sockaddr_in *)sap)->sin_port);
2165                 netid = "tcp";
2166                 netid_len = 3;
2167                 break;
2168         case AF_INET6:
2169                 if (ff_layout_ntop6_noscopeid(sap, addrbuf, sizeof(addrbuf)) == 0)
2170                         return;
2171                 port = ntohs(((struct sockaddr_in6 *)sap)->sin6_port);
2172                 netid = "tcp6";
2173                 netid_len = 4;
2174                 break;
2175         default:
2176                 /* we only support tcp and tcp6 */
2177                 WARN_ON_ONCE(1);
2178                 return;
2179         }
2180
2181         snprintf(portbuf, sizeof(portbuf), ".%u.%u", port >> 8, port & 0xff);
2182         len = strlcat(addrbuf, portbuf, sizeof(addrbuf));
2183
2184         p = xdr_reserve_space(xdr, 4 + netid_len);
2185         xdr_encode_opaque(p, netid, netid_len);
2186
2187         p = xdr_reserve_space(xdr, 4 + len);
2188         xdr_encode_opaque(p, addrbuf, len);
2189 }
2190
2191 static void
2192 ff_layout_encode_nfstime(struct xdr_stream *xdr,
2193                          ktime_t t)
2194 {
2195         struct timespec64 ts;
2196         __be32 *p;
2197
2198         p = xdr_reserve_space(xdr, 12);
2199         ts = ktime_to_timespec64(t);
2200         p = xdr_encode_hyper(p, ts.tv_sec);
2201         *p++ = cpu_to_be32(ts.tv_nsec);
2202 }
2203
2204 static void
2205 ff_layout_encode_io_latency(struct xdr_stream *xdr,
2206                             struct nfs4_ff_io_stat *stat)
2207 {
2208         __be32 *p;
2209
2210         p = xdr_reserve_space(xdr, 5 * 8);
2211         p = xdr_encode_hyper(p, stat->ops_requested);
2212         p = xdr_encode_hyper(p, stat->bytes_requested);
2213         p = xdr_encode_hyper(p, stat->ops_completed);
2214         p = xdr_encode_hyper(p, stat->bytes_completed);
2215         p = xdr_encode_hyper(p, stat->bytes_not_delivered);
2216         ff_layout_encode_nfstime(xdr, stat->total_busy_time);
2217         ff_layout_encode_nfstime(xdr, stat->aggregate_completion_time);
2218 }
2219
2220 static void
2221 ff_layout_encode_ff_layoutupdate(struct xdr_stream *xdr,
2222                               const struct nfs42_layoutstat_devinfo *devinfo,
2223                               struct nfs4_ff_layout_mirror *mirror)
2224 {
2225         struct nfs4_pnfs_ds_addr *da;
2226         struct nfs4_pnfs_ds *ds = mirror->mirror_ds->ds;
2227         struct nfs_fh *fh = &mirror->fh_versions[0];
2228         __be32 *p;
2229
2230         da = list_first_entry(&ds->ds_addrs, struct nfs4_pnfs_ds_addr, da_node);
2231         dprintk("%s: DS %s: encoding address %s\n",
2232                 __func__, ds->ds_remotestr, da->da_remotestr);
2233         /* netaddr4 */
2234         ff_layout_encode_netaddr(xdr, da);
2235         /* nfs_fh4 */
2236         p = xdr_reserve_space(xdr, 4 + fh->size);
2237         xdr_encode_opaque(p, fh->data, fh->size);
2238         /* ff_io_latency4 read */
2239         spin_lock(&mirror->lock);
2240         ff_layout_encode_io_latency(xdr, &mirror->read_stat.io_stat);
2241         /* ff_io_latency4 write */
2242         ff_layout_encode_io_latency(xdr, &mirror->write_stat.io_stat);
2243         spin_unlock(&mirror->lock);
2244         /* nfstime4 */
2245         ff_layout_encode_nfstime(xdr, ktime_sub(ktime_get(), mirror->start_time));
2246         /* bool */
2247         p = xdr_reserve_space(xdr, 4);
2248         *p = cpu_to_be32(false);
2249 }
2250
2251 static void
2252 ff_layout_encode_layoutstats(struct xdr_stream *xdr, const void *args,
2253                              const struct nfs4_xdr_opaque_data *opaque)
2254 {
2255         struct nfs42_layoutstat_devinfo *devinfo = container_of(opaque,
2256                         struct nfs42_layoutstat_devinfo, ld_private);
2257         __be32 *start;
2258
2259         /* layoutupdate length */
2260         start = xdr_reserve_space(xdr, 4);
2261         ff_layout_encode_ff_layoutupdate(xdr, devinfo, opaque->data);
2262
2263         *start = cpu_to_be32((xdr->p - start - 1) * 4);
2264 }
2265
2266 static void
2267 ff_layout_free_layoutstats(struct nfs4_xdr_opaque_data *opaque)
2268 {
2269         struct nfs4_ff_layout_mirror *mirror = opaque->data;
2270
2271         ff_layout_put_mirror(mirror);
2272 }
2273
2274 static const struct nfs4_xdr_opaque_ops layoutstat_ops = {
2275         .encode = ff_layout_encode_layoutstats,
2276         .free   = ff_layout_free_layoutstats,
2277 };
2278
2279 static int
2280 ff_layout_mirror_prepare_stats(struct pnfs_layout_hdr *lo,
2281                                struct nfs42_layoutstat_devinfo *devinfo,
2282                                int dev_limit)
2283 {
2284         struct nfs4_flexfile_layout *ff_layout = FF_LAYOUT_FROM_HDR(lo);
2285         struct nfs4_ff_layout_mirror *mirror;
2286         struct nfs4_deviceid_node *dev;
2287         int i = 0;
2288
2289         list_for_each_entry(mirror, &ff_layout->mirrors, mirrors) {
2290                 if (i >= dev_limit)
2291                         break;
2292                 if (IS_ERR_OR_NULL(mirror->mirror_ds))
2293                         continue;
2294                 if (!test_and_clear_bit(NFS4_FF_MIRROR_STAT_AVAIL, &mirror->flags))
2295                         continue;
2296                 /* mirror refcount put in cleanup_layoutstats */
2297                 if (!refcount_inc_not_zero(&mirror->ref))
2298                         continue;
2299                 dev = &mirror->mirror_ds->id_node;
2300                 memcpy(&devinfo->dev_id, &dev->deviceid, NFS4_DEVICEID4_SIZE);
2301                 devinfo->offset = 0;
2302                 devinfo->length = NFS4_MAX_UINT64;
2303                 spin_lock(&mirror->lock);
2304                 devinfo->read_count = mirror->read_stat.io_stat.ops_completed;
2305                 devinfo->read_bytes = mirror->read_stat.io_stat.bytes_completed;
2306                 devinfo->write_count = mirror->write_stat.io_stat.ops_completed;
2307                 devinfo->write_bytes = mirror->write_stat.io_stat.bytes_completed;
2308                 spin_unlock(&mirror->lock);
2309                 devinfo->layout_type = LAYOUT_FLEX_FILES;
2310                 devinfo->ld_private.ops = &layoutstat_ops;
2311                 devinfo->ld_private.data = mirror;
2312
2313                 devinfo++;
2314                 i++;
2315         }
2316         return i;
2317 }
2318
2319 static int
2320 ff_layout_prepare_layoutstats(struct nfs42_layoutstat_args *args)
2321 {
2322         struct nfs4_flexfile_layout *ff_layout;
2323         const int dev_count = PNFS_LAYOUTSTATS_MAXDEV;
2324
2325         /* For now, send at most PNFS_LAYOUTSTATS_MAXDEV statistics */
2326         args->devinfo = kmalloc_array(dev_count, sizeof(*args->devinfo), GFP_NOIO);
2327         if (!args->devinfo)
2328                 return -ENOMEM;
2329
2330         spin_lock(&args->inode->i_lock);
2331         ff_layout = FF_LAYOUT_FROM_HDR(NFS_I(args->inode)->layout);
2332         args->num_dev = ff_layout_mirror_prepare_stats(&ff_layout->generic_hdr,
2333                         &args->devinfo[0], dev_count);
2334         spin_unlock(&args->inode->i_lock);
2335         if (!args->num_dev) {
2336                 kfree(args->devinfo);
2337                 args->devinfo = NULL;
2338                 return -ENOENT;
2339         }
2340
2341         return 0;
2342 }
2343
2344 static int
2345 ff_layout_set_layoutdriver(struct nfs_server *server,
2346                 const struct nfs_fh *dummy)
2347 {
2348 #if IS_ENABLED(CONFIG_NFS_V4_2)
2349         server->caps |= NFS_CAP_LAYOUTSTATS;
2350 #endif
2351         return 0;
2352 }
2353
2354 static struct pnfs_layoutdriver_type flexfilelayout_type = {
2355         .id                     = LAYOUT_FLEX_FILES,
2356         .name                   = "LAYOUT_FLEX_FILES",
2357         .owner                  = THIS_MODULE,
2358         .flags                  = PNFS_LAYOUTGET_ON_OPEN,
2359         .max_layoutget_response = 4096, /* 1 page or so... */
2360         .set_layoutdriver       = ff_layout_set_layoutdriver,
2361         .alloc_layout_hdr       = ff_layout_alloc_layout_hdr,
2362         .free_layout_hdr        = ff_layout_free_layout_hdr,
2363         .alloc_lseg             = ff_layout_alloc_lseg,
2364         .free_lseg              = ff_layout_free_lseg,
2365         .add_lseg               = ff_layout_add_lseg,
2366         .pg_read_ops            = &ff_layout_pg_read_ops,
2367         .pg_write_ops           = &ff_layout_pg_write_ops,
2368         .get_ds_info            = ff_layout_get_ds_info,
2369         .free_deviceid_node     = ff_layout_free_deviceid_node,
2370         .mark_request_commit    = pnfs_layout_mark_request_commit,
2371         .clear_request_commit   = pnfs_generic_clear_request_commit,
2372         .scan_commit_lists      = pnfs_generic_scan_commit_lists,
2373         .recover_commit_reqs    = pnfs_generic_recover_commit_reqs,
2374         .commit_pagelist        = ff_layout_commit_pagelist,
2375         .read_pagelist          = ff_layout_read_pagelist,
2376         .write_pagelist         = ff_layout_write_pagelist,
2377         .alloc_deviceid_node    = ff_layout_alloc_deviceid_node,
2378         .prepare_layoutreturn   = ff_layout_prepare_layoutreturn,
2379         .sync                   = pnfs_nfs_generic_sync,
2380         .prepare_layoutstats    = ff_layout_prepare_layoutstats,
2381 };
2382
2383 static int __init nfs4flexfilelayout_init(void)
2384 {
2385         printk(KERN_INFO "%s: NFSv4 Flexfile Layout Driver Registering...\n",
2386                __func__);
2387         if (!ff_zero_group) {
2388                 ff_zero_group = groups_alloc(0);
2389                 if (!ff_zero_group)
2390                         return -ENOMEM;
2391         }
2392         return pnfs_register_layoutdriver(&flexfilelayout_type);
2393 }
2394
2395 static void __exit nfs4flexfilelayout_exit(void)
2396 {
2397         printk(KERN_INFO "%s: NFSv4 Flexfile Layout Driver Unregistering...\n",
2398                __func__);
2399         pnfs_unregister_layoutdriver(&flexfilelayout_type);
2400         if (ff_zero_group) {
2401                 put_group_info(ff_zero_group);
2402                 ff_zero_group = NULL;
2403         }
2404 }
2405
2406 MODULE_ALIAS("nfs-layouttype4-4");
2407
2408 MODULE_LICENSE("GPL");
2409 MODULE_DESCRIPTION("The NFSv4 flexfile layout driver");
2410
2411 module_init(nfs4flexfilelayout_init);
2412 module_exit(nfs4flexfilelayout_exit);