fs/nfsd/nfs4layouts.c

   1 /*
   2  * Copyright (c) 2014 Christoph Hellwig.
   3  */
   4 #include <linux/kmod.h>
   5 #include <linux/file.h>
   6 #include <linux/jhash.h>
   7 #include <linux/sched.h>
   8 #include <linux/sunrpc/addr.h>
   9
  10 #include "pnfs.h"
  11 #include "netns.h"
  12 #include "trace.h"
  13
  14 #define NFSDDBG_FACILITY                NFSDDBG_PNFS
  15
  16 struct nfs4_layout {
  17         struct list_head                lo_perstate;
  18         struct nfs4_layout_stateid      *lo_state;
  19         struct nfsd4_layout_seg         lo_seg;
  20 };
  21
  22 static struct kmem_cache *nfs4_layout_cache;
  23 static struct kmem_cache *nfs4_layout_stateid_cache;
  24
  25 static struct nfsd4_callback_ops nfsd4_cb_layout_ops;
  26 static const struct lock_manager_operations nfsd4_layouts_lm_ops;
  27
  28 const struct nfsd4_layout_ops *nfsd4_layout_ops[LAYOUT_TYPE_MAX] =  {
  29         [LAYOUT_BLOCK_VOLUME]   = &bl_layout_ops,
  30 };
  31
  32 /* pNFS device ID to export fsid mapping */
  33 #define DEVID_HASH_BITS 8
  34 #define DEVID_HASH_SIZE (1 << DEVID_HASH_BITS)
  35 #define DEVID_HASH_MASK (DEVID_HASH_SIZE - 1)
  36 static u64 nfsd_devid_seq = 1;
  37 static struct list_head nfsd_devid_hash[DEVID_HASH_SIZE];
  38 static DEFINE_SPINLOCK(nfsd_devid_lock);
  39
  40 static inline u32 devid_hashfn(u64 idx)
  41 {
  42         return jhash_2words(idx, idx >> 32, 0) & DEVID_HASH_MASK;
  43 }
  44
  45 static void
  46 nfsd4_alloc_devid_map(const struct svc_fh *fhp)
  47 {
  48         const struct knfsd_fh *fh = &fhp->fh_handle;
  49         size_t fsid_len = key_len(fh->fh_fsid_type);
  50         struct nfsd4_deviceid_map *map, *old;
  51         int i;
  52
  53         map = kzalloc(sizeof(*map) + fsid_len, GFP_KERNEL);
  54         if (!map)
  55                 return;
  56
  57         map->fsid_type = fh->fh_fsid_type;
  58         memcpy(&map->fsid, fh->fh_fsid, fsid_len);
  59
  60         spin_lock(&nfsd_devid_lock);
  61         if (fhp->fh_export->ex_devid_map)
  62                 goto out_unlock;
  63
  64         for (i = 0; i < DEVID_HASH_SIZE; i++) {
  65                 list_for_each_entry(old, &nfsd_devid_hash[i], hash) {
  66                         if (old->fsid_type != fh->fh_fsid_type)
  67                                 continue;
  68                         if (memcmp(old->fsid, fh->fh_fsid,
  69                                         key_len(old->fsid_type)))
  70                                 continue;
  71
  72                         fhp->fh_export->ex_devid_map = old;
  73                         goto out_unlock;
  74                 }
  75         }
  76
  77         map->idx = nfsd_devid_seq++;
  78         list_add_tail_rcu(&map->hash, &nfsd_devid_hash[devid_hashfn(map->idx)]);
  79         fhp->fh_export->ex_devid_map = map;
  80         map = NULL;
  81
  82 out_unlock:
  83         spin_unlock(&nfsd_devid_lock);
  84         kfree(map);
  85 }
  86
  87 struct nfsd4_deviceid_map *
  88 nfsd4_find_devid_map(int idx)
  89 {
  90         struct nfsd4_deviceid_map *map, *ret = NULL;
  91
  92         rcu_read_lock();
  93         list_for_each_entry_rcu(map, &nfsd_devid_hash[devid_hashfn(idx)], hash)
  94                 if (map->idx == idx)
  95                         ret = map;
  96         rcu_read_unlock();
  97
  98         return ret;
  99 }
 100
 101 int
 102 nfsd4_set_deviceid(struct nfsd4_deviceid *id, const struct svc_fh *fhp,
 103                 u32 device_generation)
 104 {
 105         if (!fhp->fh_export->ex_devid_map) {
 106                 nfsd4_alloc_devid_map(fhp);
 107                 if (!fhp->fh_export->ex_devid_map)
 108                         return -ENOMEM;
 109         }
 110
 111         id->fsid_idx = fhp->fh_export->ex_devid_map->idx;
 112         id->generation = device_generation;
 113         id->pad = 0;
 114         return 0;
 115 }
 116
 117 void nfsd4_setup_layout_type(struct svc_export *exp)
 118 {
 119         struct super_block *sb = exp->ex_path.mnt->mnt_sb;
 120
 121         if (!(exp->ex_flags & NFSEXP_PNFS))
 122                 return;
 123
 124         if (sb->s_export_op->get_uuid &&
 125             sb->s_export_op->map_blocks &&
 126             sb->s_export_op->commit_blocks)
 127                 exp->ex_layout_type = LAYOUT_BLOCK_VOLUME;
 128 }
 129
 130 static void
 131 nfsd4_free_layout_stateid(struct nfs4_stid *stid)
 132 {
 133         struct nfs4_layout_stateid *ls = layoutstateid(stid);
 134         struct nfs4_client *clp = ls->ls_stid.sc_client;
 135         struct nfs4_file *fp = ls->ls_stid.sc_file;
 136
 137         trace_layoutstate_free(&ls->ls_stid.sc_stateid);
 138
 139         spin_lock(&clp->cl_lock);
 140         list_del_init(&ls->ls_perclnt);
 141         spin_unlock(&clp->cl_lock);
 142
 143         spin_lock(&fp->fi_lock);
 144         list_del_init(&ls->ls_perfile);
 145         spin_unlock(&fp->fi_lock);
 146
 147         vfs_setlease(ls->ls_file, F_UNLCK, NULL, (void **)&ls);
 148         fput(ls->ls_file);
 149
 150         if (ls->ls_recalled)
 151                 atomic_dec(&ls->ls_stid.sc_file->fi_lo_recalls);
 152
 153         kmem_cache_free(nfs4_layout_stateid_cache, ls);
 154 }
 155
 156 static int
 157 nfsd4_layout_setlease(struct nfs4_layout_stateid *ls)
 158 {
 159         struct file_lock *fl;
 160         int status;
 161
 162         fl = locks_alloc_lock();
 163         if (!fl)
 164                 return -ENOMEM;
 165         locks_init_lock(fl);
 166         fl->fl_lmops = &nfsd4_layouts_lm_ops;
 167         fl->fl_flags = FL_LAYOUT;
 168         fl->fl_type = F_RDLCK;
 169         fl->fl_end = OFFSET_MAX;
 170         fl->fl_owner = ls;
 171         fl->fl_pid = current->tgid;
 172         fl->fl_file = ls->ls_file;
 173
 174         status = vfs_setlease(fl->fl_file, fl->fl_type, &fl, NULL);
 175         if (status) {
 176                 locks_free_lock(fl);
 177                 return status;
 178         }
 179         BUG_ON(fl != NULL);
 180         return 0;
 181 }
 182
 183 static struct nfs4_layout_stateid *
 184 nfsd4_alloc_layout_stateid(struct nfsd4_compound_state *cstate,
 185                 struct nfs4_stid *parent, u32 layout_type)
 186 {
 187         struct nfs4_client *clp = cstate->clp;
 188         struct nfs4_file *fp = parent->sc_file;
 189         struct nfs4_layout_stateid *ls;
 190         struct nfs4_stid *stp;
 191
 192         stp = nfs4_alloc_stid(cstate->clp, nfs4_layout_stateid_cache);
 193         if (!stp)
 194                 return NULL;
 195         stp->sc_free = nfsd4_free_layout_stateid;
 196         get_nfs4_file(fp);
 197         stp->sc_file = fp;
 198
 199         ls = layoutstateid(stp);
 200         INIT_LIST_HEAD(&ls->ls_perclnt);
 201         INIT_LIST_HEAD(&ls->ls_perfile);
 202         spin_lock_init(&ls->ls_lock);
 203         INIT_LIST_HEAD(&ls->ls_layouts);
 204         ls->ls_layout_type = layout_type;
 205         nfsd4_init_cb(&ls->ls_recall, clp, &nfsd4_cb_layout_ops,
 206                         NFSPROC4_CLNT_CB_LAYOUT);
 207
 208         if (parent->sc_type == NFS4_DELEG_STID)
 209                 ls->ls_file = get_file(fp->fi_deleg_file);
 210         else
 211                 ls->ls_file = find_any_file(fp);
 212         BUG_ON(!ls->ls_file);
 213
 214         if (nfsd4_layout_setlease(ls)) {
 215                 fput(ls->ls_file);
 216                 put_nfs4_file(fp);
 217                 kmem_cache_free(nfs4_layout_stateid_cache, ls);
 218                 return NULL;
 219         }
 220
 221         spin_lock(&clp->cl_lock);
 222         stp->sc_type = NFS4_LAYOUT_STID;
 223         list_add(&ls->ls_perclnt, &clp->cl_lo_states);
 224         spin_unlock(&clp->cl_lock);
 225
 226         spin_lock(&fp->fi_lock);
 227         list_add(&ls->ls_perfile, &fp->fi_lo_states);
 228         spin_unlock(&fp->fi_lock);
 229
 230         trace_layoutstate_alloc(&ls->ls_stid.sc_stateid);
 231         return ls;
 232 }
 233
 234 __be32
 235 nfsd4_preprocess_layout_stateid(struct svc_rqst *rqstp,
 236                 struct nfsd4_compound_state *cstate, stateid_t *stateid,
 237                 bool create, u32 layout_type, struct nfs4_layout_stateid **lsp)
 238 {
 239         struct nfs4_layout_stateid *ls;
 240         struct nfs4_stid *stid;
 241         unsigned char typemask = NFS4_LAYOUT_STID;
 242         __be32 status;
 243
 244         if (create)
 245                 typemask |= (NFS4_OPEN_STID | NFS4_LOCK_STID | NFS4_DELEG_STID);
 246
 247         status = nfsd4_lookup_stateid(cstate, stateid, typemask, &stid,
 248                         net_generic(SVC_NET(rqstp), nfsd_net_id));
 249         if (status)
 250                 goto out;
 251
 252         if (!fh_match(&cstate->current_fh.fh_handle,
 253                       &stid->sc_file->fi_fhandle)) {
 254                 status = nfserr_bad_stateid;
 255                 goto out_put_stid;
 256         }
 257
 258         if (stid->sc_type != NFS4_LAYOUT_STID) {
 259                 ls = nfsd4_alloc_layout_stateid(cstate, stid, layout_type);
 260                 nfs4_put_stid(stid);
 261
 262                 status = nfserr_jukebox;
 263                 if (!ls)
 264                         goto out;
 265         } else {
 266                 ls = container_of(stid, struct nfs4_layout_stateid, ls_stid);
 267
 268                 status = nfserr_bad_stateid;
 269                 if (stateid->si_generation > stid->sc_stateid.si_generation)
 270                         goto out_put_stid;
 271                 if (layout_type != ls->ls_layout_type)
 272                         goto out_put_stid;
 273         }
 274
 275         *lsp = ls;
 276         return 0;
 277
 278 out_put_stid:
 279         nfs4_put_stid(stid);
 280 out:
 281         return status;
 282 }
 283
 284 static void
 285 nfsd4_recall_file_layout(struct nfs4_layout_stateid *ls)
 286 {
 287         spin_lock(&ls->ls_lock);
 288         if (ls->ls_recalled)
 289                 goto out_unlock;
 290
 291         ls->ls_recalled = true;
 292         atomic_inc(&ls->ls_stid.sc_file->fi_lo_recalls);
 293         if (list_empty(&ls->ls_layouts))
 294                 goto out_unlock;
 295
 296         trace_layout_recall(&ls->ls_stid.sc_stateid);
 297
 298         atomic_inc(&ls->ls_stid.sc_count);
 299         update_stateid(&ls->ls_stid.sc_stateid);
 300         memcpy(&ls->ls_recall_sid, &ls->ls_stid.sc_stateid, sizeof(stateid_t));
 301         nfsd4_run_cb(&ls->ls_recall);
 302
 303 out_unlock:
 304         spin_unlock(&ls->ls_lock);
 305 }
 306
 307 static inline u64
 308 layout_end(struct nfsd4_layout_seg *seg)
 309 {
 310         u64 end = seg->offset + seg->length;
 311         return end >= seg->offset ? end : NFS4_MAX_UINT64;
 312 }
 313
 314 static void
 315 layout_update_len(struct nfsd4_layout_seg *lo, u64 end)
 316 {
 317         if (end == NFS4_MAX_UINT64)
 318                 lo->length = NFS4_MAX_UINT64;
 319         else
 320                 lo->length = end - lo->offset;
 321 }
 322
 323 static bool
 324 layouts_overlapping(struct nfs4_layout *lo, struct nfsd4_layout_seg *s)
 325 {
 326         if (s->iomode != IOMODE_ANY && s->iomode != lo->lo_seg.iomode)
 327                 return false;
 328         if (layout_end(&lo->lo_seg) <= s->offset)
 329                 return false;
 330         if (layout_end(s) <= lo->lo_seg.offset)
 331                 return false;
 332         return true;
 333 }
 334
 335 static bool
 336 layouts_try_merge(struct nfsd4_layout_seg *lo, struct nfsd4_layout_seg *new)
 337 {
 338         if (lo->iomode != new->iomode)
 339                 return false;
 340         if (layout_end(new) < lo->offset)
 341                 return false;
 342         if (layout_end(lo) < new->offset)
 343                 return false;
 344
 345         lo->offset = min(lo->offset, new->offset);
 346         layout_update_len(lo, max(layout_end(lo), layout_end(new)));
 347         return true;
 348 }
 349
 350 static __be32
 351 nfsd4_recall_conflict(struct nfs4_layout_stateid *ls)
 352 {
 353         struct nfs4_file *fp = ls->ls_stid.sc_file;
 354         struct nfs4_layout_stateid *l, *n;
 355         __be32 nfserr = nfs_ok;
 356
 357         assert_spin_locked(&fp->fi_lock);
 358
 359         list_for_each_entry_safe(l, n, &fp->fi_lo_states, ls_perfile) {
 360                 if (l != ls) {
 361                         nfsd4_recall_file_layout(l);
 362                         nfserr = nfserr_recallconflict;
 363                 }
 364         }
 365
 366         return nfserr;
 367 }
 368
 369 __be32
 370 nfsd4_insert_layout(struct nfsd4_layoutget *lgp, struct nfs4_layout_stateid *ls)
 371 {
 372         struct nfsd4_layout_seg *seg = &lgp->lg_seg;
 373         struct nfs4_file *fp = ls->ls_stid.sc_file;
 374         struct nfs4_layout *lp, *new = NULL;
 375         __be32 nfserr;
 376
 377         spin_lock(&fp->fi_lock);
 378         nfserr = nfsd4_recall_conflict(ls);
 379         if (nfserr)
 380                 goto out;
 381         spin_lock(&ls->ls_lock);
 382         list_for_each_entry(lp, &ls->ls_layouts, lo_perstate) {
 383                 if (layouts_try_merge(&lp->lo_seg, seg))
 384                         goto done;
 385         }
 386         spin_unlock(&ls->ls_lock);
 387         spin_unlock(&fp->fi_lock);
 388
 389         new = kmem_cache_alloc(nfs4_layout_cache, GFP_KERNEL);
 390         if (!new)
 391                 return nfserr_jukebox;
 392         memcpy(&new->lo_seg, seg, sizeof(lp->lo_seg));
 393         new->lo_state = ls;
 394
 395         spin_lock(&fp->fi_lock);
 396         nfserr = nfsd4_recall_conflict(ls);
 397         if (nfserr)
 398                 goto out;
 399         spin_lock(&ls->ls_lock);
 400         list_for_each_entry(lp, &ls->ls_layouts, lo_perstate) {
 401                 if (layouts_try_merge(&lp->lo_seg, seg))
 402                         goto done;
 403         }
 404
 405         atomic_inc(&ls->ls_stid.sc_count);
 406         list_add_tail(&new->lo_perstate, &ls->ls_layouts);
 407         new = NULL;
 408 done:
 409         update_stateid(&ls->ls_stid.sc_stateid);
 410         memcpy(&lgp->lg_sid, &ls->ls_stid.sc_stateid, sizeof(stateid_t));
 411         spin_unlock(&ls->ls_lock);
 412 out:
 413         spin_unlock(&fp->fi_lock);
 414         if (new)
 415                 kmem_cache_free(nfs4_layout_cache, new);
 416         return nfserr;
 417 }
 418
 419 static void
 420 nfsd4_free_layouts(struct list_head *reaplist)
 421 {
 422         while (!list_empty(reaplist)) {
 423                 struct nfs4_layout *lp = list_first_entry(reaplist,
 424                                 struct nfs4_layout, lo_perstate);
 425
 426                 list_del(&lp->lo_perstate);
 427                 nfs4_put_stid(&lp->lo_state->ls_stid);
 428                 kmem_cache_free(nfs4_layout_cache, lp);
 429         }
 430 }
 431
 432 static void
 433 nfsd4_return_file_layout(struct nfs4_layout *lp, struct nfsd4_layout_seg *seg,
 434                 struct list_head *reaplist)
 435 {
 436         struct nfsd4_layout_seg *lo = &lp->lo_seg;
 437         u64 end = layout_end(lo);
 438
 439         if (seg->offset <= lo->offset) {
 440                 if (layout_end(seg) >= end) {
 441                         list_move_tail(&lp->lo_perstate, reaplist);
 442                         return;
 443                 }
 444                 lo->offset = layout_end(seg);
 445         } else {
 446                 /* retain the whole layout segment on a split. */
 447                 if (layout_end(seg) < end) {
 448                         dprintk("%s: split not supported\n", __func__);
 449                         return;
 450                 }
 451                 end = seg->offset;
 452         }
 453
 454         layout_update_len(lo, end);
 455 }
 456
 457 __be32
 458 nfsd4_return_file_layouts(struct svc_rqst *rqstp,
 459                 struct nfsd4_compound_state *cstate,
 460                 struct nfsd4_layoutreturn *lrp)
 461 {
 462         struct nfs4_layout_stateid *ls;
 463         struct nfs4_layout *lp, *n;
 464         LIST_HEAD(reaplist);
 465         __be32 nfserr;
 466         int found = 0;
 467
 468         nfserr = nfsd4_preprocess_layout_stateid(rqstp, cstate, &lrp->lr_sid,
 469                                                 false, lrp->lr_layout_type,
 470                                                 &ls);
 471         if (nfserr) {
 472                 trace_layout_return_lookup_fail(&lrp->lr_sid);
 473                 return nfserr;
 474         }
 475
 476         spin_lock(&ls->ls_lock);
 477         list_for_each_entry_safe(lp, n, &ls->ls_layouts, lo_perstate) {
 478                 if (layouts_overlapping(lp, &lrp->lr_seg)) {
 479                         nfsd4_return_file_layout(lp, &lrp->lr_seg, &reaplist);
 480                         found++;
 481                 }
 482         }
 483         if (!list_empty(&ls->ls_layouts)) {
 484                 if (found) {
 485                         update_stateid(&ls->ls_stid.sc_stateid);
 486                         memcpy(&lrp->lr_sid, &ls->ls_stid.sc_stateid,
 487                                 sizeof(stateid_t));
 488                 }
 489                 lrp->lrs_present = 1;
 490         } else {
 491                 trace_layoutstate_unhash(&ls->ls_stid.sc_stateid);
 492                 nfs4_unhash_stid(&ls->ls_stid);
 493                 lrp->lrs_present = 0;
 494         }
 495         spin_unlock(&ls->ls_lock);
 496
 497         nfs4_put_stid(&ls->ls_stid);
 498         nfsd4_free_layouts(&reaplist);
 499         return nfs_ok;
 500 }
 501
 502 __be32
 503 nfsd4_return_client_layouts(struct svc_rqst *rqstp,
 504                 struct nfsd4_compound_state *cstate,
 505                 struct nfsd4_layoutreturn *lrp)
 506 {
 507         struct nfs4_layout_stateid *ls, *n;
 508         struct nfs4_client *clp = cstate->clp;
 509         struct nfs4_layout *lp, *t;
 510         LIST_HEAD(reaplist);
 511
 512         lrp->lrs_present = 0;
 513
 514         spin_lock(&clp->cl_lock);
 515         list_for_each_entry_safe(ls, n, &clp->cl_lo_states, ls_perclnt) {
 516                 if (ls->ls_layout_type != lrp->lr_layout_type)
 517                         continue;
 518
 519                 if (lrp->lr_return_type == RETURN_FSID &&
 520                     !fh_fsid_match(&ls->ls_stid.sc_file->fi_fhandle,
 521                                    &cstate->current_fh.fh_handle))
 522                         continue;
 523
 524                 spin_lock(&ls->ls_lock);
 525                 list_for_each_entry_safe(lp, t, &ls->ls_layouts, lo_perstate) {
 526                         if (lrp->lr_seg.iomode == IOMODE_ANY ||
 527                             lrp->lr_seg.iomode == lp->lo_seg.iomode)
 528                                 list_move_tail(&lp->lo_perstate, &reaplist);
 529                 }
 530                 spin_unlock(&ls->ls_lock);
 531         }
 532         spin_unlock(&clp->cl_lock);
 533
 534         nfsd4_free_layouts(&reaplist);
 535         return 0;
 536 }
 537
 538 static void
 539 nfsd4_return_all_layouts(struct nfs4_layout_stateid *ls,
 540                 struct list_head *reaplist)
 541 {
 542         spin_lock(&ls->ls_lock);
 543         list_splice_init(&ls->ls_layouts, reaplist);
 544         spin_unlock(&ls->ls_lock);
 545 }
 546
 547 void
 548 nfsd4_return_all_client_layouts(struct nfs4_client *clp)
 549 {
 550         struct nfs4_layout_stateid *ls, *n;
 551         LIST_HEAD(reaplist);
 552
 553         spin_lock(&clp->cl_lock);
 554         list_for_each_entry_safe(ls, n, &clp->cl_lo_states, ls_perclnt)
 555                 nfsd4_return_all_layouts(ls, &reaplist);
 556         spin_unlock(&clp->cl_lock);
 557
 558         nfsd4_free_layouts(&reaplist);
 559 }
 560
 561 void
 562 nfsd4_return_all_file_layouts(struct nfs4_client *clp, struct nfs4_file *fp)
 563 {
 564         struct nfs4_layout_stateid *ls, *n;
 565         LIST_HEAD(reaplist);
 566
 567         spin_lock(&fp->fi_lock);
 568         list_for_each_entry_safe(ls, n, &fp->fi_lo_states, ls_perfile) {
 569                 if (ls->ls_stid.sc_client == clp)
 570                         nfsd4_return_all_layouts(ls, &reaplist);
 571         }
 572         spin_unlock(&fp->fi_lock);
 573
 574         nfsd4_free_layouts(&reaplist);
 575 }
 576
 577 static void
 578 nfsd4_cb_layout_fail(struct nfs4_layout_stateid *ls)
 579 {
 580         struct nfs4_client *clp = ls->ls_stid.sc_client;
 581         char addr_str[INET6_ADDRSTRLEN];
 582         static char *envp[] = {
 583                 "HOME=/",
 584                 "TERM=linux",
 585                 "PATH=/sbin:/usr/sbin:/bin:/usr/bin",
 586                 NULL
 587         };
 588         char *argv[8];
 589         int error;
 590
 591         rpc_ntop((struct sockaddr *)&clp->cl_addr, addr_str, sizeof(addr_str));
 592
 593         trace_layout_recall_fail(&ls->ls_stid.sc_stateid);
 594
 595         printk(KERN_WARNING
 596                 "nfsd: client %s failed to respond to layout recall. "
 597                 "  Fencing..\n", addr_str);
 598
 599         argv[0] = "/sbin/nfsd-recall-failed";
 600         argv[1] = addr_str;
 601         argv[2] = ls->ls_file->f_path.mnt->mnt_sb->s_id;
 602         argv[3] = NULL;
 603
 604         error = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_PROC);
 605         if (error) {
 606                 printk(KERN_ERR "nfsd: fence failed for client %s: %d!\n",
 607                         addr_str, error);
 608         }
 609 }
 610
 611 static int
 612 nfsd4_cb_layout_done(struct nfsd4_callback *cb, struct rpc_task *task)
 613 {
 614         struct nfs4_layout_stateid *ls =
 615                 container_of(cb, struct nfs4_layout_stateid, ls_recall);
 616         LIST_HEAD(reaplist);
 617
 618         switch (task->tk_status) {
 619         case 0:
 620                 return 1;
 621         case -NFS4ERR_NOMATCHING_LAYOUT:
 622                 trace_layout_recall_done(&ls->ls_stid.sc_stateid);
 623                 task->tk_status = 0;
 624                 return 1;
 625         case -NFS4ERR_DELAY:
 626                 /* Poll the client until it's done with the layout */
 627                 /* FIXME: cap number of retries.
 628                  * The pnfs standard states that we need to only expire
 629                  * the client after at-least "lease time" .eg lease-time * 2
 630                  * when failing to communicate a recall
 631                  */
 632                 rpc_delay(task, HZ/100); /* 10 mili-seconds */
 633                 return 0;
 634         default:
 635                 /*
 636                  * Unknown error or non-responding client, we'll need to fence.
 637                  */
 638                 nfsd4_cb_layout_fail(ls);
 639                 return -1;
 640         }
 641 }
 642
 643 static void
 644 nfsd4_cb_layout_release(struct nfsd4_callback *cb)
 645 {
 646         struct nfs4_layout_stateid *ls =
 647                 container_of(cb, struct nfs4_layout_stateid, ls_recall);
 648         LIST_HEAD(reaplist);
 649
 650         trace_layout_recall_release(&ls->ls_stid.sc_stateid);
 651
 652         nfsd4_return_all_layouts(ls, &reaplist);
 653         nfsd4_free_layouts(&reaplist);
 654         nfs4_put_stid(&ls->ls_stid);
 655 }
 656
 657 static struct nfsd4_callback_ops nfsd4_cb_layout_ops = {
 658         .done           = nfsd4_cb_layout_done,
 659         .release        = nfsd4_cb_layout_release,
 660 };
 661
 662 static bool
 663 nfsd4_layout_lm_break(struct file_lock *fl)
 664 {
 665         /*
 666          * We don't want the locks code to timeout the lease for us;
 667          * we'll remove it ourself if a layout isn't returned
 668          * in time:
 669          */
 670         fl->fl_break_time = 0;
 671         nfsd4_recall_file_layout(fl->fl_owner);
 672         return false;
 673 }
 674
 675 static int
 676 nfsd4_layout_lm_change(struct file_lock *onlist, int arg,
 677                 struct list_head *dispose)
 678 {
 679         BUG_ON(!(arg & F_UNLCK));
 680         return lease_modify(onlist, arg, dispose);
 681 }
 682
 683 static const struct lock_manager_operations nfsd4_layouts_lm_ops = {
 684         .lm_break       = nfsd4_layout_lm_break,
 685         .lm_change      = nfsd4_layout_lm_change,
 686 };
 687
 688 int
 689 nfsd4_init_pnfs(void)
 690 {
 691         int i;
 692
 693         for (i = 0; i < DEVID_HASH_SIZE; i++)
 694                 INIT_LIST_HEAD(&nfsd_devid_hash[i]);
 695
 696         nfs4_layout_cache = kmem_cache_create("nfs4_layout",
 697                         sizeof(struct nfs4_layout), 0, 0, NULL);
 698         if (!nfs4_layout_cache)
 699                 return -ENOMEM;
 700
 701         nfs4_layout_stateid_cache = kmem_cache_create("nfs4_layout_stateid",
 702                         sizeof(struct nfs4_layout_stateid), 0, 0, NULL);
 703         if (!nfs4_layout_stateid_cache) {
 704                 kmem_cache_destroy(nfs4_layout_cache);
 705                 return -ENOMEM;
 706         }
 707         return 0;
 708 }
 709
 710 void
 711 nfsd4_exit_pnfs(void)
 712 {
 713         int i;
 714
 715         kmem_cache_destroy(nfs4_layout_cache);
 716         kmem_cache_destroy(nfs4_layout_stateid_cache);
 717
 718         for (i = 0; i < DEVID_HASH_SIZE; i++) {
 719                 struct nfsd4_deviceid_map *map, *n;
 720
 721                 list_for_each_entry_safe(map, n, &nfsd_devid_hash[i], hash)
 722                         kfree(map);
 723         }
 724 }