xref: /openbmc/linux/fs/nfsd/nfs4layouts.c (revision 2cf1c348)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2014 Christoph Hellwig.
4  */
5 #include <linux/blkdev.h>
6 #include <linux/kmod.h>
7 #include <linux/file.h>
8 #include <linux/jhash.h>
9 #include <linux/sched.h>
10 #include <linux/sunrpc/addr.h>
11 
12 #include "pnfs.h"
13 #include "netns.h"
14 #include "trace.h"
15 
16 #define NFSDDBG_FACILITY                NFSDDBG_PNFS
17 
18 struct nfs4_layout {
19 	struct list_head		lo_perstate;
20 	struct nfs4_layout_stateid	*lo_state;
21 	struct nfsd4_layout_seg		lo_seg;
22 };
23 
24 static struct kmem_cache *nfs4_layout_cache;
25 static struct kmem_cache *nfs4_layout_stateid_cache;
26 
27 static const struct nfsd4_callback_ops nfsd4_cb_layout_ops;
28 static const struct lock_manager_operations nfsd4_layouts_lm_ops;
29 
30 const struct nfsd4_layout_ops *nfsd4_layout_ops[LAYOUT_TYPE_MAX] =  {
31 #ifdef CONFIG_NFSD_FLEXFILELAYOUT
32 	[LAYOUT_FLEX_FILES]	= &ff_layout_ops,
33 #endif
34 #ifdef CONFIG_NFSD_BLOCKLAYOUT
35 	[LAYOUT_BLOCK_VOLUME]	= &bl_layout_ops,
36 #endif
37 #ifdef CONFIG_NFSD_SCSILAYOUT
38 	[LAYOUT_SCSI]		= &scsi_layout_ops,
39 #endif
40 };
41 
42 /* pNFS device ID to export fsid mapping */
43 #define DEVID_HASH_BITS	8
44 #define DEVID_HASH_SIZE	(1 << DEVID_HASH_BITS)
45 #define DEVID_HASH_MASK	(DEVID_HASH_SIZE - 1)
46 static u64 nfsd_devid_seq = 1;
47 static struct list_head nfsd_devid_hash[DEVID_HASH_SIZE];
48 static DEFINE_SPINLOCK(nfsd_devid_lock);
49 
50 static inline u32 devid_hashfn(u64 idx)
51 {
52 	return jhash_2words(idx, idx >> 32, 0) & DEVID_HASH_MASK;
53 }
54 
55 static void
56 nfsd4_alloc_devid_map(const struct svc_fh *fhp)
57 {
58 	const struct knfsd_fh *fh = &fhp->fh_handle;
59 	size_t fsid_len = key_len(fh->fh_fsid_type);
60 	struct nfsd4_deviceid_map *map, *old;
61 	int i;
62 
63 	map = kzalloc(sizeof(*map) + fsid_len, GFP_KERNEL);
64 	if (!map)
65 		return;
66 
67 	map->fsid_type = fh->fh_fsid_type;
68 	memcpy(&map->fsid, fh->fh_fsid, fsid_len);
69 
70 	spin_lock(&nfsd_devid_lock);
71 	if (fhp->fh_export->ex_devid_map)
72 		goto out_unlock;
73 
74 	for (i = 0; i < DEVID_HASH_SIZE; i++) {
75 		list_for_each_entry(old, &nfsd_devid_hash[i], hash) {
76 			if (old->fsid_type != fh->fh_fsid_type)
77 				continue;
78 			if (memcmp(old->fsid, fh->fh_fsid,
79 					key_len(old->fsid_type)))
80 				continue;
81 
82 			fhp->fh_export->ex_devid_map = old;
83 			goto out_unlock;
84 		}
85 	}
86 
87 	map->idx = nfsd_devid_seq++;
88 	list_add_tail_rcu(&map->hash, &nfsd_devid_hash[devid_hashfn(map->idx)]);
89 	fhp->fh_export->ex_devid_map = map;
90 	map = NULL;
91 
92 out_unlock:
93 	spin_unlock(&nfsd_devid_lock);
94 	kfree(map);
95 }
96 
97 struct nfsd4_deviceid_map *
98 nfsd4_find_devid_map(int idx)
99 {
100 	struct nfsd4_deviceid_map *map, *ret = NULL;
101 
102 	rcu_read_lock();
103 	list_for_each_entry_rcu(map, &nfsd_devid_hash[devid_hashfn(idx)], hash)
104 		if (map->idx == idx)
105 			ret = map;
106 	rcu_read_unlock();
107 
108 	return ret;
109 }
110 
111 int
112 nfsd4_set_deviceid(struct nfsd4_deviceid *id, const struct svc_fh *fhp,
113 		u32 device_generation)
114 {
115 	if (!fhp->fh_export->ex_devid_map) {
116 		nfsd4_alloc_devid_map(fhp);
117 		if (!fhp->fh_export->ex_devid_map)
118 			return -ENOMEM;
119 	}
120 
121 	id->fsid_idx = fhp->fh_export->ex_devid_map->idx;
122 	id->generation = device_generation;
123 	id->pad = 0;
124 	return 0;
125 }
126 
127 void nfsd4_setup_layout_type(struct svc_export *exp)
128 {
129 #if defined(CONFIG_NFSD_BLOCKLAYOUT) || defined(CONFIG_NFSD_SCSILAYOUT)
130 	struct super_block *sb = exp->ex_path.mnt->mnt_sb;
131 #endif
132 
133 	if (!(exp->ex_flags & NFSEXP_PNFS))
134 		return;
135 
136 #ifdef CONFIG_NFSD_FLEXFILELAYOUT
137 	exp->ex_layout_types |= 1 << LAYOUT_FLEX_FILES;
138 #endif
139 #ifdef CONFIG_NFSD_BLOCKLAYOUT
140 	if (sb->s_export_op->get_uuid &&
141 	    sb->s_export_op->map_blocks &&
142 	    sb->s_export_op->commit_blocks)
143 		exp->ex_layout_types |= 1 << LAYOUT_BLOCK_VOLUME;
144 #endif
145 #ifdef CONFIG_NFSD_SCSILAYOUT
146 	if (sb->s_export_op->map_blocks &&
147 	    sb->s_export_op->commit_blocks &&
148 	    sb->s_bdev &&
149 	    sb->s_bdev->bd_disk->fops->pr_ops &&
150 	    sb->s_bdev->bd_disk->fops->get_unique_id)
151 		exp->ex_layout_types |= 1 << LAYOUT_SCSI;
152 #endif
153 }
154 
155 static void
156 nfsd4_free_layout_stateid(struct nfs4_stid *stid)
157 {
158 	struct nfs4_layout_stateid *ls = layoutstateid(stid);
159 	struct nfs4_client *clp = ls->ls_stid.sc_client;
160 	struct nfs4_file *fp = ls->ls_stid.sc_file;
161 
162 	trace_nfsd_layoutstate_free(&ls->ls_stid.sc_stateid);
163 
164 	spin_lock(&clp->cl_lock);
165 	list_del_init(&ls->ls_perclnt);
166 	spin_unlock(&clp->cl_lock);
167 
168 	spin_lock(&fp->fi_lock);
169 	list_del_init(&ls->ls_perfile);
170 	spin_unlock(&fp->fi_lock);
171 
172 	if (!nfsd4_layout_ops[ls->ls_layout_type]->disable_recalls)
173 		vfs_setlease(ls->ls_file->nf_file, F_UNLCK, NULL, (void **)&ls);
174 	nfsd_file_put(ls->ls_file);
175 
176 	if (ls->ls_recalled)
177 		atomic_dec(&ls->ls_stid.sc_file->fi_lo_recalls);
178 
179 	kmem_cache_free(nfs4_layout_stateid_cache, ls);
180 }
181 
182 static int
183 nfsd4_layout_setlease(struct nfs4_layout_stateid *ls)
184 {
185 	struct file_lock *fl;
186 	int status;
187 
188 	if (nfsd4_layout_ops[ls->ls_layout_type]->disable_recalls)
189 		return 0;
190 
191 	fl = locks_alloc_lock();
192 	if (!fl)
193 		return -ENOMEM;
194 	locks_init_lock(fl);
195 	fl->fl_lmops = &nfsd4_layouts_lm_ops;
196 	fl->fl_flags = FL_LAYOUT;
197 	fl->fl_type = F_RDLCK;
198 	fl->fl_end = OFFSET_MAX;
199 	fl->fl_owner = ls;
200 	fl->fl_pid = current->tgid;
201 	fl->fl_file = ls->ls_file->nf_file;
202 
203 	status = vfs_setlease(fl->fl_file, fl->fl_type, &fl, NULL);
204 	if (status) {
205 		locks_free_lock(fl);
206 		return status;
207 	}
208 	BUG_ON(fl != NULL);
209 	return 0;
210 }
211 
212 static struct nfs4_layout_stateid *
213 nfsd4_alloc_layout_stateid(struct nfsd4_compound_state *cstate,
214 		struct nfs4_stid *parent, u32 layout_type)
215 {
216 	struct nfs4_client *clp = cstate->clp;
217 	struct nfs4_file *fp = parent->sc_file;
218 	struct nfs4_layout_stateid *ls;
219 	struct nfs4_stid *stp;
220 
221 	stp = nfs4_alloc_stid(cstate->clp, nfs4_layout_stateid_cache,
222 					nfsd4_free_layout_stateid);
223 	if (!stp)
224 		return NULL;
225 
226 	get_nfs4_file(fp);
227 	stp->sc_file = fp;
228 
229 	ls = layoutstateid(stp);
230 	INIT_LIST_HEAD(&ls->ls_perclnt);
231 	INIT_LIST_HEAD(&ls->ls_perfile);
232 	spin_lock_init(&ls->ls_lock);
233 	INIT_LIST_HEAD(&ls->ls_layouts);
234 	mutex_init(&ls->ls_mutex);
235 	ls->ls_layout_type = layout_type;
236 	nfsd4_init_cb(&ls->ls_recall, clp, &nfsd4_cb_layout_ops,
237 			NFSPROC4_CLNT_CB_LAYOUT);
238 
239 	if (parent->sc_type == NFS4_DELEG_STID)
240 		ls->ls_file = nfsd_file_get(fp->fi_deleg_file);
241 	else
242 		ls->ls_file = find_any_file(fp);
243 	BUG_ON(!ls->ls_file);
244 
245 	if (nfsd4_layout_setlease(ls)) {
246 		nfsd_file_put(ls->ls_file);
247 		put_nfs4_file(fp);
248 		kmem_cache_free(nfs4_layout_stateid_cache, ls);
249 		return NULL;
250 	}
251 
252 	spin_lock(&clp->cl_lock);
253 	stp->sc_type = NFS4_LAYOUT_STID;
254 	list_add(&ls->ls_perclnt, &clp->cl_lo_states);
255 	spin_unlock(&clp->cl_lock);
256 
257 	spin_lock(&fp->fi_lock);
258 	list_add(&ls->ls_perfile, &fp->fi_lo_states);
259 	spin_unlock(&fp->fi_lock);
260 
261 	trace_nfsd_layoutstate_alloc(&ls->ls_stid.sc_stateid);
262 	return ls;
263 }
264 
265 __be32
266 nfsd4_preprocess_layout_stateid(struct svc_rqst *rqstp,
267 		struct nfsd4_compound_state *cstate, stateid_t *stateid,
268 		bool create, u32 layout_type, struct nfs4_layout_stateid **lsp)
269 {
270 	struct nfs4_layout_stateid *ls;
271 	struct nfs4_stid *stid;
272 	unsigned char typemask = NFS4_LAYOUT_STID;
273 	__be32 status;
274 
275 	if (create)
276 		typemask |= (NFS4_OPEN_STID | NFS4_LOCK_STID | NFS4_DELEG_STID);
277 
278 	status = nfsd4_lookup_stateid(cstate, stateid, typemask, &stid,
279 			net_generic(SVC_NET(rqstp), nfsd_net_id));
280 	if (status)
281 		goto out;
282 
283 	if (!fh_match(&cstate->current_fh.fh_handle,
284 		      &stid->sc_file->fi_fhandle)) {
285 		status = nfserr_bad_stateid;
286 		goto out_put_stid;
287 	}
288 
289 	if (stid->sc_type != NFS4_LAYOUT_STID) {
290 		ls = nfsd4_alloc_layout_stateid(cstate, stid, layout_type);
291 		nfs4_put_stid(stid);
292 
293 		status = nfserr_jukebox;
294 		if (!ls)
295 			goto out;
296 		mutex_lock(&ls->ls_mutex);
297 	} else {
298 		ls = container_of(stid, struct nfs4_layout_stateid, ls_stid);
299 
300 		status = nfserr_bad_stateid;
301 		mutex_lock(&ls->ls_mutex);
302 		if (nfsd4_stateid_generation_after(stateid, &stid->sc_stateid))
303 			goto out_unlock_stid;
304 		if (layout_type != ls->ls_layout_type)
305 			goto out_unlock_stid;
306 	}
307 
308 	*lsp = ls;
309 	return 0;
310 
311 out_unlock_stid:
312 	mutex_unlock(&ls->ls_mutex);
313 out_put_stid:
314 	nfs4_put_stid(stid);
315 out:
316 	return status;
317 }
318 
319 static void
320 nfsd4_recall_file_layout(struct nfs4_layout_stateid *ls)
321 {
322 	spin_lock(&ls->ls_lock);
323 	if (ls->ls_recalled)
324 		goto out_unlock;
325 
326 	ls->ls_recalled = true;
327 	atomic_inc(&ls->ls_stid.sc_file->fi_lo_recalls);
328 	if (list_empty(&ls->ls_layouts))
329 		goto out_unlock;
330 
331 	trace_nfsd_layout_recall(&ls->ls_stid.sc_stateid);
332 
333 	refcount_inc(&ls->ls_stid.sc_count);
334 	nfsd4_run_cb(&ls->ls_recall);
335 
336 out_unlock:
337 	spin_unlock(&ls->ls_lock);
338 }
339 
340 static inline u64
341 layout_end(struct nfsd4_layout_seg *seg)
342 {
343 	u64 end = seg->offset + seg->length;
344 	return end >= seg->offset ? end : NFS4_MAX_UINT64;
345 }
346 
347 static void
348 layout_update_len(struct nfsd4_layout_seg *lo, u64 end)
349 {
350 	if (end == NFS4_MAX_UINT64)
351 		lo->length = NFS4_MAX_UINT64;
352 	else
353 		lo->length = end - lo->offset;
354 }
355 
356 static bool
357 layouts_overlapping(struct nfs4_layout *lo, struct nfsd4_layout_seg *s)
358 {
359 	if (s->iomode != IOMODE_ANY && s->iomode != lo->lo_seg.iomode)
360 		return false;
361 	if (layout_end(&lo->lo_seg) <= s->offset)
362 		return false;
363 	if (layout_end(s) <= lo->lo_seg.offset)
364 		return false;
365 	return true;
366 }
367 
368 static bool
369 layouts_try_merge(struct nfsd4_layout_seg *lo, struct nfsd4_layout_seg *new)
370 {
371 	if (lo->iomode != new->iomode)
372 		return false;
373 	if (layout_end(new) < lo->offset)
374 		return false;
375 	if (layout_end(lo) < new->offset)
376 		return false;
377 
378 	lo->offset = min(lo->offset, new->offset);
379 	layout_update_len(lo, max(layout_end(lo), layout_end(new)));
380 	return true;
381 }
382 
383 static __be32
384 nfsd4_recall_conflict(struct nfs4_layout_stateid *ls)
385 {
386 	struct nfs4_file *fp = ls->ls_stid.sc_file;
387 	struct nfs4_layout_stateid *l, *n;
388 	__be32 nfserr = nfs_ok;
389 
390 	assert_spin_locked(&fp->fi_lock);
391 
392 	list_for_each_entry_safe(l, n, &fp->fi_lo_states, ls_perfile) {
393 		if (l != ls) {
394 			nfsd4_recall_file_layout(l);
395 			nfserr = nfserr_recallconflict;
396 		}
397 	}
398 
399 	return nfserr;
400 }
401 
402 __be32
403 nfsd4_insert_layout(struct nfsd4_layoutget *lgp, struct nfs4_layout_stateid *ls)
404 {
405 	struct nfsd4_layout_seg *seg = &lgp->lg_seg;
406 	struct nfs4_file *fp = ls->ls_stid.sc_file;
407 	struct nfs4_layout *lp, *new = NULL;
408 	__be32 nfserr;
409 
410 	spin_lock(&fp->fi_lock);
411 	nfserr = nfsd4_recall_conflict(ls);
412 	if (nfserr)
413 		goto out;
414 	spin_lock(&ls->ls_lock);
415 	list_for_each_entry(lp, &ls->ls_layouts, lo_perstate) {
416 		if (layouts_try_merge(&lp->lo_seg, seg))
417 			goto done;
418 	}
419 	spin_unlock(&ls->ls_lock);
420 	spin_unlock(&fp->fi_lock);
421 
422 	new = kmem_cache_alloc(nfs4_layout_cache, GFP_KERNEL);
423 	if (!new)
424 		return nfserr_jukebox;
425 	memcpy(&new->lo_seg, seg, sizeof(lp->lo_seg));
426 	new->lo_state = ls;
427 
428 	spin_lock(&fp->fi_lock);
429 	nfserr = nfsd4_recall_conflict(ls);
430 	if (nfserr)
431 		goto out;
432 	spin_lock(&ls->ls_lock);
433 	list_for_each_entry(lp, &ls->ls_layouts, lo_perstate) {
434 		if (layouts_try_merge(&lp->lo_seg, seg))
435 			goto done;
436 	}
437 
438 	refcount_inc(&ls->ls_stid.sc_count);
439 	list_add_tail(&new->lo_perstate, &ls->ls_layouts);
440 	new = NULL;
441 done:
442 	nfs4_inc_and_copy_stateid(&lgp->lg_sid, &ls->ls_stid);
443 	spin_unlock(&ls->ls_lock);
444 out:
445 	spin_unlock(&fp->fi_lock);
446 	if (new)
447 		kmem_cache_free(nfs4_layout_cache, new);
448 	return nfserr;
449 }
450 
451 static void
452 nfsd4_free_layouts(struct list_head *reaplist)
453 {
454 	while (!list_empty(reaplist)) {
455 		struct nfs4_layout *lp = list_first_entry(reaplist,
456 				struct nfs4_layout, lo_perstate);
457 
458 		list_del(&lp->lo_perstate);
459 		nfs4_put_stid(&lp->lo_state->ls_stid);
460 		kmem_cache_free(nfs4_layout_cache, lp);
461 	}
462 }
463 
464 static void
465 nfsd4_return_file_layout(struct nfs4_layout *lp, struct nfsd4_layout_seg *seg,
466 		struct list_head *reaplist)
467 {
468 	struct nfsd4_layout_seg *lo = &lp->lo_seg;
469 	u64 end = layout_end(lo);
470 
471 	if (seg->offset <= lo->offset) {
472 		if (layout_end(seg) >= end) {
473 			list_move_tail(&lp->lo_perstate, reaplist);
474 			return;
475 		}
476 		lo->offset = layout_end(seg);
477 	} else {
478 		/* retain the whole layout segment on a split. */
479 		if (layout_end(seg) < end) {
480 			dprintk("%s: split not supported\n", __func__);
481 			return;
482 		}
483 		end = seg->offset;
484 	}
485 
486 	layout_update_len(lo, end);
487 }
488 
489 __be32
490 nfsd4_return_file_layouts(struct svc_rqst *rqstp,
491 		struct nfsd4_compound_state *cstate,
492 		struct nfsd4_layoutreturn *lrp)
493 {
494 	struct nfs4_layout_stateid *ls;
495 	struct nfs4_layout *lp, *n;
496 	LIST_HEAD(reaplist);
497 	__be32 nfserr;
498 	int found = 0;
499 
500 	nfserr = nfsd4_preprocess_layout_stateid(rqstp, cstate, &lrp->lr_sid,
501 						false, lrp->lr_layout_type,
502 						&ls);
503 	if (nfserr) {
504 		trace_nfsd_layout_return_lookup_fail(&lrp->lr_sid);
505 		return nfserr;
506 	}
507 
508 	spin_lock(&ls->ls_lock);
509 	list_for_each_entry_safe(lp, n, &ls->ls_layouts, lo_perstate) {
510 		if (layouts_overlapping(lp, &lrp->lr_seg)) {
511 			nfsd4_return_file_layout(lp, &lrp->lr_seg, &reaplist);
512 			found++;
513 		}
514 	}
515 	if (!list_empty(&ls->ls_layouts)) {
516 		if (found)
517 			nfs4_inc_and_copy_stateid(&lrp->lr_sid, &ls->ls_stid);
518 		lrp->lrs_present = 1;
519 	} else {
520 		trace_nfsd_layoutstate_unhash(&ls->ls_stid.sc_stateid);
521 		nfs4_unhash_stid(&ls->ls_stid);
522 		lrp->lrs_present = 0;
523 	}
524 	spin_unlock(&ls->ls_lock);
525 
526 	mutex_unlock(&ls->ls_mutex);
527 	nfs4_put_stid(&ls->ls_stid);
528 	nfsd4_free_layouts(&reaplist);
529 	return nfs_ok;
530 }
531 
532 __be32
533 nfsd4_return_client_layouts(struct svc_rqst *rqstp,
534 		struct nfsd4_compound_state *cstate,
535 		struct nfsd4_layoutreturn *lrp)
536 {
537 	struct nfs4_layout_stateid *ls, *n;
538 	struct nfs4_client *clp = cstate->clp;
539 	struct nfs4_layout *lp, *t;
540 	LIST_HEAD(reaplist);
541 
542 	lrp->lrs_present = 0;
543 
544 	spin_lock(&clp->cl_lock);
545 	list_for_each_entry_safe(ls, n, &clp->cl_lo_states, ls_perclnt) {
546 		if (ls->ls_layout_type != lrp->lr_layout_type)
547 			continue;
548 
549 		if (lrp->lr_return_type == RETURN_FSID &&
550 		    !fh_fsid_match(&ls->ls_stid.sc_file->fi_fhandle,
551 				   &cstate->current_fh.fh_handle))
552 			continue;
553 
554 		spin_lock(&ls->ls_lock);
555 		list_for_each_entry_safe(lp, t, &ls->ls_layouts, lo_perstate) {
556 			if (lrp->lr_seg.iomode == IOMODE_ANY ||
557 			    lrp->lr_seg.iomode == lp->lo_seg.iomode)
558 				list_move_tail(&lp->lo_perstate, &reaplist);
559 		}
560 		spin_unlock(&ls->ls_lock);
561 	}
562 	spin_unlock(&clp->cl_lock);
563 
564 	nfsd4_free_layouts(&reaplist);
565 	return 0;
566 }
567 
568 static void
569 nfsd4_return_all_layouts(struct nfs4_layout_stateid *ls,
570 		struct list_head *reaplist)
571 {
572 	spin_lock(&ls->ls_lock);
573 	list_splice_init(&ls->ls_layouts, reaplist);
574 	spin_unlock(&ls->ls_lock);
575 }
576 
577 void
578 nfsd4_return_all_client_layouts(struct nfs4_client *clp)
579 {
580 	struct nfs4_layout_stateid *ls, *n;
581 	LIST_HEAD(reaplist);
582 
583 	spin_lock(&clp->cl_lock);
584 	list_for_each_entry_safe(ls, n, &clp->cl_lo_states, ls_perclnt)
585 		nfsd4_return_all_layouts(ls, &reaplist);
586 	spin_unlock(&clp->cl_lock);
587 
588 	nfsd4_free_layouts(&reaplist);
589 }
590 
591 void
592 nfsd4_return_all_file_layouts(struct nfs4_client *clp, struct nfs4_file *fp)
593 {
594 	struct nfs4_layout_stateid *ls, *n;
595 	LIST_HEAD(reaplist);
596 
597 	spin_lock(&fp->fi_lock);
598 	list_for_each_entry_safe(ls, n, &fp->fi_lo_states, ls_perfile) {
599 		if (ls->ls_stid.sc_client == clp)
600 			nfsd4_return_all_layouts(ls, &reaplist);
601 	}
602 	spin_unlock(&fp->fi_lock);
603 
604 	nfsd4_free_layouts(&reaplist);
605 }
606 
607 static void
608 nfsd4_cb_layout_fail(struct nfs4_layout_stateid *ls)
609 {
610 	struct nfs4_client *clp = ls->ls_stid.sc_client;
611 	char addr_str[INET6_ADDRSTRLEN];
612 	static char const nfsd_recall_failed[] = "/sbin/nfsd-recall-failed";
613 	static char *envp[] = {
614 		"HOME=/",
615 		"TERM=linux",
616 		"PATH=/sbin:/usr/sbin:/bin:/usr/bin",
617 		NULL
618 	};
619 	char *argv[8];
620 	int error;
621 
622 	rpc_ntop((struct sockaddr *)&clp->cl_addr, addr_str, sizeof(addr_str));
623 
624 	printk(KERN_WARNING
625 		"nfsd: client %s failed to respond to layout recall. "
626 		"  Fencing..\n", addr_str);
627 
628 	argv[0] = (char *)nfsd_recall_failed;
629 	argv[1] = addr_str;
630 	argv[2] = ls->ls_file->nf_file->f_path.mnt->mnt_sb->s_id;
631 	argv[3] = NULL;
632 
633 	error = call_usermodehelper(nfsd_recall_failed, argv, envp,
634 				    UMH_WAIT_PROC);
635 	if (error) {
636 		printk(KERN_ERR "nfsd: fence failed for client %s: %d!\n",
637 			addr_str, error);
638 	}
639 }
640 
641 static void
642 nfsd4_cb_layout_prepare(struct nfsd4_callback *cb)
643 {
644 	struct nfs4_layout_stateid *ls =
645 		container_of(cb, struct nfs4_layout_stateid, ls_recall);
646 
647 	mutex_lock(&ls->ls_mutex);
648 	nfs4_inc_and_copy_stateid(&ls->ls_recall_sid, &ls->ls_stid);
649 	mutex_unlock(&ls->ls_mutex);
650 }
651 
652 static int
653 nfsd4_cb_layout_done(struct nfsd4_callback *cb, struct rpc_task *task)
654 {
655 	struct nfs4_layout_stateid *ls =
656 		container_of(cb, struct nfs4_layout_stateid, ls_recall);
657 	struct nfsd_net *nn;
658 	ktime_t now, cutoff;
659 	const struct nfsd4_layout_ops *ops;
660 
661 
662 	switch (task->tk_status) {
663 	case 0:
664 	case -NFS4ERR_DELAY:
665 		/*
666 		 * Anything left? If not, then call it done. Note that we don't
667 		 * take the spinlock since this is an optimization and nothing
668 		 * should get added until the cb counter goes to zero.
669 		 */
670 		if (list_empty(&ls->ls_layouts))
671 			return 1;
672 
673 		/* Poll the client until it's done with the layout */
674 		now = ktime_get();
675 		nn = net_generic(ls->ls_stid.sc_client->net, nfsd_net_id);
676 
677 		/* Client gets 2 lease periods to return it */
678 		cutoff = ktime_add_ns(task->tk_start,
679 					 (u64)nn->nfsd4_lease * NSEC_PER_SEC * 2);
680 
681 		if (ktime_before(now, cutoff)) {
682 			rpc_delay(task, HZ/100); /* 10 mili-seconds */
683 			return 0;
684 		}
685 		fallthrough;
686 	default:
687 		/*
688 		 * Unknown error or non-responding client, we'll need to fence.
689 		 */
690 		trace_nfsd_layout_recall_fail(&ls->ls_stid.sc_stateid);
691 
692 		ops = nfsd4_layout_ops[ls->ls_layout_type];
693 		if (ops->fence_client)
694 			ops->fence_client(ls);
695 		else
696 			nfsd4_cb_layout_fail(ls);
697 		return 1;
698 	case -NFS4ERR_NOMATCHING_LAYOUT:
699 		trace_nfsd_layout_recall_done(&ls->ls_stid.sc_stateid);
700 		task->tk_status = 0;
701 		return 1;
702 	}
703 }
704 
705 static void
706 nfsd4_cb_layout_release(struct nfsd4_callback *cb)
707 {
708 	struct nfs4_layout_stateid *ls =
709 		container_of(cb, struct nfs4_layout_stateid, ls_recall);
710 	LIST_HEAD(reaplist);
711 
712 	trace_nfsd_layout_recall_release(&ls->ls_stid.sc_stateid);
713 
714 	nfsd4_return_all_layouts(ls, &reaplist);
715 	nfsd4_free_layouts(&reaplist);
716 	nfs4_put_stid(&ls->ls_stid);
717 }
718 
719 static const struct nfsd4_callback_ops nfsd4_cb_layout_ops = {
720 	.prepare	= nfsd4_cb_layout_prepare,
721 	.done		= nfsd4_cb_layout_done,
722 	.release	= nfsd4_cb_layout_release,
723 };
724 
725 static bool
726 nfsd4_layout_lm_break(struct file_lock *fl)
727 {
728 	/*
729 	 * We don't want the locks code to timeout the lease for us;
730 	 * we'll remove it ourself if a layout isn't returned
731 	 * in time:
732 	 */
733 	fl->fl_break_time = 0;
734 	nfsd4_recall_file_layout(fl->fl_owner);
735 	return false;
736 }
737 
738 static int
739 nfsd4_layout_lm_change(struct file_lock *onlist, int arg,
740 		struct list_head *dispose)
741 {
742 	BUG_ON(!(arg & F_UNLCK));
743 	return lease_modify(onlist, arg, dispose);
744 }
745 
746 static const struct lock_manager_operations nfsd4_layouts_lm_ops = {
747 	.lm_break	= nfsd4_layout_lm_break,
748 	.lm_change	= nfsd4_layout_lm_change,
749 };
750 
751 int
752 nfsd4_init_pnfs(void)
753 {
754 	int i;
755 
756 	for (i = 0; i < DEVID_HASH_SIZE; i++)
757 		INIT_LIST_HEAD(&nfsd_devid_hash[i]);
758 
759 	nfs4_layout_cache = kmem_cache_create("nfs4_layout",
760 			sizeof(struct nfs4_layout), 0, 0, NULL);
761 	if (!nfs4_layout_cache)
762 		return -ENOMEM;
763 
764 	nfs4_layout_stateid_cache = kmem_cache_create("nfs4_layout_stateid",
765 			sizeof(struct nfs4_layout_stateid), 0, 0, NULL);
766 	if (!nfs4_layout_stateid_cache) {
767 		kmem_cache_destroy(nfs4_layout_cache);
768 		return -ENOMEM;
769 	}
770 	return 0;
771 }
772 
773 void
774 nfsd4_exit_pnfs(void)
775 {
776 	int i;
777 
778 	kmem_cache_destroy(nfs4_layout_cache);
779 	kmem_cache_destroy(nfs4_layout_stateid_cache);
780 
781 	for (i = 0; i < DEVID_HASH_SIZE; i++) {
782 		struct nfsd4_deviceid_map *map, *n;
783 
784 		list_for_each_entry_safe(map, n, &nfsd_devid_hash[i], hash)
785 			kfree(map);
786 	}
787 }
788