drm/i915: Fix comments about GMBUSFREQ register
[linux-2.6-microblaze.git] / fs / nfsd / nfs4layouts.c
1 /*
2  * Copyright (c) 2014 Christoph Hellwig.
3  */
4 #include <linux/blkdev.h>
5 #include <linux/kmod.h>
6 #include <linux/file.h>
7 #include <linux/jhash.h>
8 #include <linux/sched.h>
9 #include <linux/sunrpc/addr.h>
10
11 #include "pnfs.h"
12 #include "netns.h"
13 #include "trace.h"
14
15 #define NFSDDBG_FACILITY                NFSDDBG_PNFS
16
17 struct nfs4_layout {
18         struct list_head                lo_perstate;
19         struct nfs4_layout_stateid      *lo_state;
20         struct nfsd4_layout_seg         lo_seg;
21 };
22
23 static struct kmem_cache *nfs4_layout_cache;
24 static struct kmem_cache *nfs4_layout_stateid_cache;
25
26 static const struct nfsd4_callback_ops nfsd4_cb_layout_ops;
27 static const struct lock_manager_operations nfsd4_layouts_lm_ops;
28
29 const struct nfsd4_layout_ops *nfsd4_layout_ops[LAYOUT_TYPE_MAX] =  {
30 #ifdef CONFIG_NFSD_BLOCKLAYOUT
31         [LAYOUT_BLOCK_VOLUME]   = &bl_layout_ops,
32 #endif
33 #ifdef CONFIG_NFSD_SCSILAYOUT
34         [LAYOUT_SCSI]           = &scsi_layout_ops,
35 #endif
36 };
37
38 /* pNFS device ID to export fsid mapping */
39 #define DEVID_HASH_BITS 8
40 #define DEVID_HASH_SIZE (1 << DEVID_HASH_BITS)
41 #define DEVID_HASH_MASK (DEVID_HASH_SIZE - 1)
42 static u64 nfsd_devid_seq = 1;
43 static struct list_head nfsd_devid_hash[DEVID_HASH_SIZE];
44 static DEFINE_SPINLOCK(nfsd_devid_lock);
45
46 static inline u32 devid_hashfn(u64 idx)
47 {
48         return jhash_2words(idx, idx >> 32, 0) & DEVID_HASH_MASK;
49 }
50
51 static void
52 nfsd4_alloc_devid_map(const struct svc_fh *fhp)
53 {
54         const struct knfsd_fh *fh = &fhp->fh_handle;
55         size_t fsid_len = key_len(fh->fh_fsid_type);
56         struct nfsd4_deviceid_map *map, *old;
57         int i;
58
59         map = kzalloc(sizeof(*map) + fsid_len, GFP_KERNEL);
60         if (!map)
61                 return;
62
63         map->fsid_type = fh->fh_fsid_type;
64         memcpy(&map->fsid, fh->fh_fsid, fsid_len);
65
66         spin_lock(&nfsd_devid_lock);
67         if (fhp->fh_export->ex_devid_map)
68                 goto out_unlock;
69
70         for (i = 0; i < DEVID_HASH_SIZE; i++) {
71                 list_for_each_entry(old, &nfsd_devid_hash[i], hash) {
72                         if (old->fsid_type != fh->fh_fsid_type)
73                                 continue;
74                         if (memcmp(old->fsid, fh->fh_fsid,
75                                         key_len(old->fsid_type)))
76                                 continue;
77
78                         fhp->fh_export->ex_devid_map = old;
79                         goto out_unlock;
80                 }
81         }
82
83         map->idx = nfsd_devid_seq++;
84         list_add_tail_rcu(&map->hash, &nfsd_devid_hash[devid_hashfn(map->idx)]);
85         fhp->fh_export->ex_devid_map = map;
86         map = NULL;
87
88 out_unlock:
89         spin_unlock(&nfsd_devid_lock);
90         kfree(map);
91 }
92
93 struct nfsd4_deviceid_map *
94 nfsd4_find_devid_map(int idx)
95 {
96         struct nfsd4_deviceid_map *map, *ret = NULL;
97
98         rcu_read_lock();
99         list_for_each_entry_rcu(map, &nfsd_devid_hash[devid_hashfn(idx)], hash)
100                 if (map->idx == idx)
101                         ret = map;
102         rcu_read_unlock();
103
104         return ret;
105 }
106
107 int
108 nfsd4_set_deviceid(struct nfsd4_deviceid *id, const struct svc_fh *fhp,
109                 u32 device_generation)
110 {
111         if (!fhp->fh_export->ex_devid_map) {
112                 nfsd4_alloc_devid_map(fhp);
113                 if (!fhp->fh_export->ex_devid_map)
114                         return -ENOMEM;
115         }
116
117         id->fsid_idx = fhp->fh_export->ex_devid_map->idx;
118         id->generation = device_generation;
119         id->pad = 0;
120         return 0;
121 }
122
123 void nfsd4_setup_layout_type(struct svc_export *exp)
124 {
125         struct super_block *sb = exp->ex_path.mnt->mnt_sb;
126
127         if (!(exp->ex_flags & NFSEXP_PNFS))
128                 return;
129
130         /*
131          * Check if the file system supports exporting a block-like layout.
132          * If the block device supports reservations prefer the SCSI layout,
133          * otherwise advertise the block layout.
134          */
135 #ifdef CONFIG_NFSD_BLOCKLAYOUT
136         if (sb->s_export_op->get_uuid &&
137             sb->s_export_op->map_blocks &&
138             sb->s_export_op->commit_blocks)
139                 exp->ex_layout_type = LAYOUT_BLOCK_VOLUME;
140 #endif
141 #ifdef CONFIG_NFSD_SCSILAYOUT
142         /* overwrite block layout selection if needed */
143         if (sb->s_export_op->map_blocks &&
144             sb->s_export_op->commit_blocks &&
145             sb->s_bdev && sb->s_bdev->bd_disk->fops->pr_ops)
146                 exp->ex_layout_type = LAYOUT_SCSI;
147 #endif
148 }
149
150 static void
151 nfsd4_free_layout_stateid(struct nfs4_stid *stid)
152 {
153         struct nfs4_layout_stateid *ls = layoutstateid(stid);
154         struct nfs4_client *clp = ls->ls_stid.sc_client;
155         struct nfs4_file *fp = ls->ls_stid.sc_file;
156
157         trace_layoutstate_free(&ls->ls_stid.sc_stateid);
158
159         spin_lock(&clp->cl_lock);
160         list_del_init(&ls->ls_perclnt);
161         spin_unlock(&clp->cl_lock);
162
163         spin_lock(&fp->fi_lock);
164         list_del_init(&ls->ls_perfile);
165         spin_unlock(&fp->fi_lock);
166
167         vfs_setlease(ls->ls_file, F_UNLCK, NULL, (void **)&ls);
168         fput(ls->ls_file);
169
170         if (ls->ls_recalled)
171                 atomic_dec(&ls->ls_stid.sc_file->fi_lo_recalls);
172
173         kmem_cache_free(nfs4_layout_stateid_cache, ls);
174 }
175
176 static int
177 nfsd4_layout_setlease(struct nfs4_layout_stateid *ls)
178 {
179         struct file_lock *fl;
180         int status;
181
182         fl = locks_alloc_lock();
183         if (!fl)
184                 return -ENOMEM;
185         locks_init_lock(fl);
186         fl->fl_lmops = &nfsd4_layouts_lm_ops;
187         fl->fl_flags = FL_LAYOUT;
188         fl->fl_type = F_RDLCK;
189         fl->fl_end = OFFSET_MAX;
190         fl->fl_owner = ls;
191         fl->fl_pid = current->tgid;
192         fl->fl_file = ls->ls_file;
193
194         status = vfs_setlease(fl->fl_file, fl->fl_type, &fl, NULL);
195         if (status) {
196                 locks_free_lock(fl);
197                 return status;
198         }
199         BUG_ON(fl != NULL);
200         return 0;
201 }
202
203 static struct nfs4_layout_stateid *
204 nfsd4_alloc_layout_stateid(struct nfsd4_compound_state *cstate,
205                 struct nfs4_stid *parent, u32 layout_type)
206 {
207         struct nfs4_client *clp = cstate->clp;
208         struct nfs4_file *fp = parent->sc_file;
209         struct nfs4_layout_stateid *ls;
210         struct nfs4_stid *stp;
211
212         stp = nfs4_alloc_stid(cstate->clp, nfs4_layout_stateid_cache);
213         if (!stp)
214                 return NULL;
215         stp->sc_free = nfsd4_free_layout_stateid;
216         get_nfs4_file(fp);
217         stp->sc_file = fp;
218
219         ls = layoutstateid(stp);
220         INIT_LIST_HEAD(&ls->ls_perclnt);
221         INIT_LIST_HEAD(&ls->ls_perfile);
222         spin_lock_init(&ls->ls_lock);
223         INIT_LIST_HEAD(&ls->ls_layouts);
224         mutex_init(&ls->ls_mutex);
225         ls->ls_layout_type = layout_type;
226         nfsd4_init_cb(&ls->ls_recall, clp, &nfsd4_cb_layout_ops,
227                         NFSPROC4_CLNT_CB_LAYOUT);
228
229         if (parent->sc_type == NFS4_DELEG_STID)
230                 ls->ls_file = get_file(fp->fi_deleg_file);
231         else
232                 ls->ls_file = find_any_file(fp);
233         BUG_ON(!ls->ls_file);
234
235         if (nfsd4_layout_setlease(ls)) {
236                 fput(ls->ls_file);
237                 put_nfs4_file(fp);
238                 kmem_cache_free(nfs4_layout_stateid_cache, ls);
239                 return NULL;
240         }
241
242         spin_lock(&clp->cl_lock);
243         stp->sc_type = NFS4_LAYOUT_STID;
244         list_add(&ls->ls_perclnt, &clp->cl_lo_states);
245         spin_unlock(&clp->cl_lock);
246
247         spin_lock(&fp->fi_lock);
248         list_add(&ls->ls_perfile, &fp->fi_lo_states);
249         spin_unlock(&fp->fi_lock);
250
251         trace_layoutstate_alloc(&ls->ls_stid.sc_stateid);
252         return ls;
253 }
254
255 __be32
256 nfsd4_preprocess_layout_stateid(struct svc_rqst *rqstp,
257                 struct nfsd4_compound_state *cstate, stateid_t *stateid,
258                 bool create, u32 layout_type, struct nfs4_layout_stateid **lsp)
259 {
260         struct nfs4_layout_stateid *ls;
261         struct nfs4_stid *stid;
262         unsigned char typemask = NFS4_LAYOUT_STID;
263         __be32 status;
264
265         if (create)
266                 typemask |= (NFS4_OPEN_STID | NFS4_LOCK_STID | NFS4_DELEG_STID);
267
268         status = nfsd4_lookup_stateid(cstate, stateid, typemask, &stid,
269                         net_generic(SVC_NET(rqstp), nfsd_net_id));
270         if (status)
271                 goto out;
272
273         if (!fh_match(&cstate->current_fh.fh_handle,
274                       &stid->sc_file->fi_fhandle)) {
275                 status = nfserr_bad_stateid;
276                 goto out_put_stid;
277         }
278
279         if (stid->sc_type != NFS4_LAYOUT_STID) {
280                 ls = nfsd4_alloc_layout_stateid(cstate, stid, layout_type);
281                 nfs4_put_stid(stid);
282
283                 status = nfserr_jukebox;
284                 if (!ls)
285                         goto out;
286                 mutex_lock(&ls->ls_mutex);
287         } else {
288                 ls = container_of(stid, struct nfs4_layout_stateid, ls_stid);
289
290                 status = nfserr_bad_stateid;
291                 mutex_lock(&ls->ls_mutex);
292                 if (stateid->si_generation > stid->sc_stateid.si_generation)
293                         goto out_unlock_stid;
294                 if (layout_type != ls->ls_layout_type)
295                         goto out_unlock_stid;
296         }
297
298         *lsp = ls;
299         return 0;
300
301 out_unlock_stid:
302         mutex_unlock(&ls->ls_mutex);
303 out_put_stid:
304         nfs4_put_stid(stid);
305 out:
306         return status;
307 }
308
309 static void
310 nfsd4_recall_file_layout(struct nfs4_layout_stateid *ls)
311 {
312         spin_lock(&ls->ls_lock);
313         if (ls->ls_recalled)
314                 goto out_unlock;
315
316         ls->ls_recalled = true;
317         atomic_inc(&ls->ls_stid.sc_file->fi_lo_recalls);
318         if (list_empty(&ls->ls_layouts))
319                 goto out_unlock;
320
321         trace_layout_recall(&ls->ls_stid.sc_stateid);
322
323         atomic_inc(&ls->ls_stid.sc_count);
324         nfsd4_run_cb(&ls->ls_recall);
325
326 out_unlock:
327         spin_unlock(&ls->ls_lock);
328 }
329
330 static inline u64
331 layout_end(struct nfsd4_layout_seg *seg)
332 {
333         u64 end = seg->offset + seg->length;
334         return end >= seg->offset ? end : NFS4_MAX_UINT64;
335 }
336
337 static void
338 layout_update_len(struct nfsd4_layout_seg *lo, u64 end)
339 {
340         if (end == NFS4_MAX_UINT64)
341                 lo->length = NFS4_MAX_UINT64;
342         else
343                 lo->length = end - lo->offset;
344 }
345
346 static bool
347 layouts_overlapping(struct nfs4_layout *lo, struct nfsd4_layout_seg *s)
348 {
349         if (s->iomode != IOMODE_ANY && s->iomode != lo->lo_seg.iomode)
350                 return false;
351         if (layout_end(&lo->lo_seg) <= s->offset)
352                 return false;
353         if (layout_end(s) <= lo->lo_seg.offset)
354                 return false;
355         return true;
356 }
357
358 static bool
359 layouts_try_merge(struct nfsd4_layout_seg *lo, struct nfsd4_layout_seg *new)
360 {
361         if (lo->iomode != new->iomode)
362                 return false;
363         if (layout_end(new) < lo->offset)
364                 return false;
365         if (layout_end(lo) < new->offset)
366                 return false;
367
368         lo->offset = min(lo->offset, new->offset);
369         layout_update_len(lo, max(layout_end(lo), layout_end(new)));
370         return true;
371 }
372
373 static __be32
374 nfsd4_recall_conflict(struct nfs4_layout_stateid *ls)
375 {
376         struct nfs4_file *fp = ls->ls_stid.sc_file;
377         struct nfs4_layout_stateid *l, *n;
378         __be32 nfserr = nfs_ok;
379
380         assert_spin_locked(&fp->fi_lock);
381
382         list_for_each_entry_safe(l, n, &fp->fi_lo_states, ls_perfile) {
383                 if (l != ls) {
384                         nfsd4_recall_file_layout(l);
385                         nfserr = nfserr_recallconflict;
386                 }
387         }
388
389         return nfserr;
390 }
391
392 __be32
393 nfsd4_insert_layout(struct nfsd4_layoutget *lgp, struct nfs4_layout_stateid *ls)
394 {
395         struct nfsd4_layout_seg *seg = &lgp->lg_seg;
396         struct nfs4_file *fp = ls->ls_stid.sc_file;
397         struct nfs4_layout *lp, *new = NULL;
398         __be32 nfserr;
399
400         spin_lock(&fp->fi_lock);
401         nfserr = nfsd4_recall_conflict(ls);
402         if (nfserr)
403                 goto out;
404         spin_lock(&ls->ls_lock);
405         list_for_each_entry(lp, &ls->ls_layouts, lo_perstate) {
406                 if (layouts_try_merge(&lp->lo_seg, seg))
407                         goto done;
408         }
409         spin_unlock(&ls->ls_lock);
410         spin_unlock(&fp->fi_lock);
411
412         new = kmem_cache_alloc(nfs4_layout_cache, GFP_KERNEL);
413         if (!new)
414                 return nfserr_jukebox;
415         memcpy(&new->lo_seg, seg, sizeof(lp->lo_seg));
416         new->lo_state = ls;
417
418         spin_lock(&fp->fi_lock);
419         nfserr = nfsd4_recall_conflict(ls);
420         if (nfserr)
421                 goto out;
422         spin_lock(&ls->ls_lock);
423         list_for_each_entry(lp, &ls->ls_layouts, lo_perstate) {
424                 if (layouts_try_merge(&lp->lo_seg, seg))
425                         goto done;
426         }
427
428         atomic_inc(&ls->ls_stid.sc_count);
429         list_add_tail(&new->lo_perstate, &ls->ls_layouts);
430         new = NULL;
431 done:
432         nfs4_inc_and_copy_stateid(&lgp->lg_sid, &ls->ls_stid);
433         spin_unlock(&ls->ls_lock);
434 out:
435         spin_unlock(&fp->fi_lock);
436         if (new)
437                 kmem_cache_free(nfs4_layout_cache, new);
438         return nfserr;
439 }
440
441 static void
442 nfsd4_free_layouts(struct list_head *reaplist)
443 {
444         while (!list_empty(reaplist)) {
445                 struct nfs4_layout *lp = list_first_entry(reaplist,
446                                 struct nfs4_layout, lo_perstate);
447
448                 list_del(&lp->lo_perstate);
449                 nfs4_put_stid(&lp->lo_state->ls_stid);
450                 kmem_cache_free(nfs4_layout_cache, lp);
451         }
452 }
453
454 static void
455 nfsd4_return_file_layout(struct nfs4_layout *lp, struct nfsd4_layout_seg *seg,
456                 struct list_head *reaplist)
457 {
458         struct nfsd4_layout_seg *lo = &lp->lo_seg;
459         u64 end = layout_end(lo);
460
461         if (seg->offset <= lo->offset) {
462                 if (layout_end(seg) >= end) {
463                         list_move_tail(&lp->lo_perstate, reaplist);
464                         return;
465                 }
466                 lo->offset = layout_end(seg);
467         } else {
468                 /* retain the whole layout segment on a split. */
469                 if (layout_end(seg) < end) {
470                         dprintk("%s: split not supported\n", __func__);
471                         return;
472                 }
473                 end = seg->offset;
474         }
475
476         layout_update_len(lo, end);
477 }
478
479 __be32
480 nfsd4_return_file_layouts(struct svc_rqst *rqstp,
481                 struct nfsd4_compound_state *cstate,
482                 struct nfsd4_layoutreturn *lrp)
483 {
484         struct nfs4_layout_stateid *ls;
485         struct nfs4_layout *lp, *n;
486         LIST_HEAD(reaplist);
487         __be32 nfserr;
488         int found = 0;
489
490         nfserr = nfsd4_preprocess_layout_stateid(rqstp, cstate, &lrp->lr_sid,
491                                                 false, lrp->lr_layout_type,
492                                                 &ls);
493         if (nfserr) {
494                 trace_layout_return_lookup_fail(&lrp->lr_sid);
495                 return nfserr;
496         }
497
498         spin_lock(&ls->ls_lock);
499         list_for_each_entry_safe(lp, n, &ls->ls_layouts, lo_perstate) {
500                 if (layouts_overlapping(lp, &lrp->lr_seg)) {
501                         nfsd4_return_file_layout(lp, &lrp->lr_seg, &reaplist);
502                         found++;
503                 }
504         }
505         if (!list_empty(&ls->ls_layouts)) {
506                 if (found)
507                         nfs4_inc_and_copy_stateid(&lrp->lr_sid, &ls->ls_stid);
508                 lrp->lrs_present = 1;
509         } else {
510                 trace_layoutstate_unhash(&ls->ls_stid.sc_stateid);
511                 nfs4_unhash_stid(&ls->ls_stid);
512                 lrp->lrs_present = 0;
513         }
514         spin_unlock(&ls->ls_lock);
515
516         mutex_unlock(&ls->ls_mutex);
517         nfs4_put_stid(&ls->ls_stid);
518         nfsd4_free_layouts(&reaplist);
519         return nfs_ok;
520 }
521
522 __be32
523 nfsd4_return_client_layouts(struct svc_rqst *rqstp,
524                 struct nfsd4_compound_state *cstate,
525                 struct nfsd4_layoutreturn *lrp)
526 {
527         struct nfs4_layout_stateid *ls, *n;
528         struct nfs4_client *clp = cstate->clp;
529         struct nfs4_layout *lp, *t;
530         LIST_HEAD(reaplist);
531
532         lrp->lrs_present = 0;
533
534         spin_lock(&clp->cl_lock);
535         list_for_each_entry_safe(ls, n, &clp->cl_lo_states, ls_perclnt) {
536                 if (ls->ls_layout_type != lrp->lr_layout_type)
537                         continue;
538
539                 if (lrp->lr_return_type == RETURN_FSID &&
540                     !fh_fsid_match(&ls->ls_stid.sc_file->fi_fhandle,
541                                    &cstate->current_fh.fh_handle))
542                         continue;
543
544                 spin_lock(&ls->ls_lock);
545                 list_for_each_entry_safe(lp, t, &ls->ls_layouts, lo_perstate) {
546                         if (lrp->lr_seg.iomode == IOMODE_ANY ||
547                             lrp->lr_seg.iomode == lp->lo_seg.iomode)
548                                 list_move_tail(&lp->lo_perstate, &reaplist);
549                 }
550                 spin_unlock(&ls->ls_lock);
551         }
552         spin_unlock(&clp->cl_lock);
553
554         nfsd4_free_layouts(&reaplist);
555         return 0;
556 }
557
558 static void
559 nfsd4_return_all_layouts(struct nfs4_layout_stateid *ls,
560                 struct list_head *reaplist)
561 {
562         spin_lock(&ls->ls_lock);
563         list_splice_init(&ls->ls_layouts, reaplist);
564         spin_unlock(&ls->ls_lock);
565 }
566
567 void
568 nfsd4_return_all_client_layouts(struct nfs4_client *clp)
569 {
570         struct nfs4_layout_stateid *ls, *n;
571         LIST_HEAD(reaplist);
572
573         spin_lock(&clp->cl_lock);
574         list_for_each_entry_safe(ls, n, &clp->cl_lo_states, ls_perclnt)
575                 nfsd4_return_all_layouts(ls, &reaplist);
576         spin_unlock(&clp->cl_lock);
577
578         nfsd4_free_layouts(&reaplist);
579 }
580
581 void
582 nfsd4_return_all_file_layouts(struct nfs4_client *clp, struct nfs4_file *fp)
583 {
584         struct nfs4_layout_stateid *ls, *n;
585         LIST_HEAD(reaplist);
586
587         spin_lock(&fp->fi_lock);
588         list_for_each_entry_safe(ls, n, &fp->fi_lo_states, ls_perfile) {
589                 if (ls->ls_stid.sc_client == clp)
590                         nfsd4_return_all_layouts(ls, &reaplist);
591         }
592         spin_unlock(&fp->fi_lock);
593
594         nfsd4_free_layouts(&reaplist);
595 }
596
597 static void
598 nfsd4_cb_layout_fail(struct nfs4_layout_stateid *ls)
599 {
600         struct nfs4_client *clp = ls->ls_stid.sc_client;
601         char addr_str[INET6_ADDRSTRLEN];
602         static char *envp[] = {
603                 "HOME=/",
604                 "TERM=linux",
605                 "PATH=/sbin:/usr/sbin:/bin:/usr/bin",
606                 NULL
607         };
608         char *argv[8];
609         int error;
610
611         rpc_ntop((struct sockaddr *)&clp->cl_addr, addr_str, sizeof(addr_str));
612
613         printk(KERN_WARNING
614                 "nfsd: client %s failed to respond to layout recall. "
615                 "  Fencing..\n", addr_str);
616
617         argv[0] = "/sbin/nfsd-recall-failed";
618         argv[1] = addr_str;
619         argv[2] = ls->ls_file->f_path.mnt->mnt_sb->s_id;
620         argv[3] = NULL;
621
622         error = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_PROC);
623         if (error) {
624                 printk(KERN_ERR "nfsd: fence failed for client %s: %d!\n",
625                         addr_str, error);
626         }
627 }
628
629 static void
630 nfsd4_cb_layout_prepare(struct nfsd4_callback *cb)
631 {
632         struct nfs4_layout_stateid *ls =
633                 container_of(cb, struct nfs4_layout_stateid, ls_recall);
634
635         mutex_lock(&ls->ls_mutex);
636         nfs4_inc_and_copy_stateid(&ls->ls_recall_sid, &ls->ls_stid);
637         mutex_unlock(&ls->ls_mutex);
638 }
639
640 static int
641 nfsd4_cb_layout_done(struct nfsd4_callback *cb, struct rpc_task *task)
642 {
643         struct nfs4_layout_stateid *ls =
644                 container_of(cb, struct nfs4_layout_stateid, ls_recall);
645         struct nfsd_net *nn;
646         ktime_t now, cutoff;
647         const struct nfsd4_layout_ops *ops;
648         LIST_HEAD(reaplist);
649
650
651         switch (task->tk_status) {
652         case 0:
653         case -NFS4ERR_DELAY:
654                 /*
655                  * Anything left? If not, then call it done. Note that we don't
656                  * take the spinlock since this is an optimization and nothing
657                  * should get added until the cb counter goes to zero.
658                  */
659                 if (list_empty(&ls->ls_layouts))
660                         return 1;
661
662                 /* Poll the client until it's done with the layout */
663                 now = ktime_get();
664                 nn = net_generic(ls->ls_stid.sc_client->net, nfsd_net_id);
665
666                 /* Client gets 2 lease periods to return it */
667                 cutoff = ktime_add_ns(task->tk_start,
668                                          nn->nfsd4_lease * NSEC_PER_SEC * 2);
669
670                 if (ktime_before(now, cutoff)) {
671                         rpc_delay(task, HZ/100); /* 10 mili-seconds */
672                         return 0;
673                 }
674                 /* Fallthrough */
675         case -NFS4ERR_NOMATCHING_LAYOUT:
676                 trace_layout_recall_done(&ls->ls_stid.sc_stateid);
677                 task->tk_status = 0;
678                 return 1;
679         default:
680                 /*
681                  * Unknown error or non-responding client, we'll need to fence.
682                  */
683                 trace_layout_recall_fail(&ls->ls_stid.sc_stateid);
684
685                 ops = nfsd4_layout_ops[ls->ls_layout_type];
686                 if (ops->fence_client)
687                         ops->fence_client(ls);
688                 else
689                         nfsd4_cb_layout_fail(ls);
690                 return -1;
691         }
692 }
693
694 static void
695 nfsd4_cb_layout_release(struct nfsd4_callback *cb)
696 {
697         struct nfs4_layout_stateid *ls =
698                 container_of(cb, struct nfs4_layout_stateid, ls_recall);
699         LIST_HEAD(reaplist);
700
701         trace_layout_recall_release(&ls->ls_stid.sc_stateid);
702
703         nfsd4_return_all_layouts(ls, &reaplist);
704         nfsd4_free_layouts(&reaplist);
705         nfs4_put_stid(&ls->ls_stid);
706 }
707
708 static const struct nfsd4_callback_ops nfsd4_cb_layout_ops = {
709         .prepare        = nfsd4_cb_layout_prepare,
710         .done           = nfsd4_cb_layout_done,
711         .release        = nfsd4_cb_layout_release,
712 };
713
714 static bool
715 nfsd4_layout_lm_break(struct file_lock *fl)
716 {
717         /*
718          * We don't want the locks code to timeout the lease for us;
719          * we'll remove it ourself if a layout isn't returned
720          * in time:
721          */
722         fl->fl_break_time = 0;
723         nfsd4_recall_file_layout(fl->fl_owner);
724         return false;
725 }
726
727 static int
728 nfsd4_layout_lm_change(struct file_lock *onlist, int arg,
729                 struct list_head *dispose)
730 {
731         BUG_ON(!(arg & F_UNLCK));
732         return lease_modify(onlist, arg, dispose);
733 }
734
735 static const struct lock_manager_operations nfsd4_layouts_lm_ops = {
736         .lm_break       = nfsd4_layout_lm_break,
737         .lm_change      = nfsd4_layout_lm_change,
738 };
739
740 int
741 nfsd4_init_pnfs(void)
742 {
743         int i;
744
745         for (i = 0; i < DEVID_HASH_SIZE; i++)
746                 INIT_LIST_HEAD(&nfsd_devid_hash[i]);
747
748         nfs4_layout_cache = kmem_cache_create("nfs4_layout",
749                         sizeof(struct nfs4_layout), 0, 0, NULL);
750         if (!nfs4_layout_cache)
751                 return -ENOMEM;
752
753         nfs4_layout_stateid_cache = kmem_cache_create("nfs4_layout_stateid",
754                         sizeof(struct nfs4_layout_stateid), 0, 0, NULL);
755         if (!nfs4_layout_stateid_cache) {
756                 kmem_cache_destroy(nfs4_layout_cache);
757                 return -ENOMEM;
758         }
759         return 0;
760 }
761
762 void
763 nfsd4_exit_pnfs(void)
764 {
765         int i;
766
767         kmem_cache_destroy(nfs4_layout_cache);
768         kmem_cache_destroy(nfs4_layout_stateid_cache);
769
770         for (i = 0; i < DEVID_HASH_SIZE; i++) {
771                 struct nfsd4_deviceid_map *map, *n;
772
773                 list_for_each_entry_safe(map, n, &nfsd_devid_hash[i], hash)
774                         kfree(map);
775         }
776 }