xref: /openbmc/linux/fs/nfs/nfs4client.c (revision ff6defa6)
1 /*
2  * Copyright (C) 2006 Red Hat, Inc. All Rights Reserved.
3  * Written by David Howells (dhowells@redhat.com)
4  */
5 #include <linux/module.h>
6 #include <linux/nfs_fs.h>
7 #include <linux/nfs_idmap.h>
8 #include <linux/nfs_mount.h>
9 #include <linux/sunrpc/addr.h>
10 #include <linux/sunrpc/auth.h>
11 #include <linux/sunrpc/xprt.h>
12 #include <linux/sunrpc/bc_xprt.h>
13 #include <linux/sunrpc/rpc_pipe_fs.h>
14 #include "internal.h"
15 #include "callback.h"
16 #include "delegation.h"
17 #include "nfs4session.h"
18 #include "pnfs.h"
19 #include "netns.h"
20 
21 #define NFSDBG_FACILITY		NFSDBG_CLIENT
22 
23 /*
24  * Get a unique NFSv4.0 callback identifier which will be used
25  * by the V4.0 callback service to lookup the nfs_client struct
26  */
27 static int nfs_get_cb_ident_idr(struct nfs_client *clp, int minorversion)
28 {
29 	int ret = 0;
30 	struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
31 
32 	if (clp->rpc_ops->version != 4 || minorversion != 0)
33 		return ret;
34 	idr_preload(GFP_KERNEL);
35 	spin_lock(&nn->nfs_client_lock);
36 	ret = idr_alloc(&nn->cb_ident_idr, clp, 0, 0, GFP_NOWAIT);
37 	if (ret >= 0)
38 		clp->cl_cb_ident = ret;
39 	spin_unlock(&nn->nfs_client_lock);
40 	idr_preload_end();
41 	return ret < 0 ? ret : 0;
42 }
43 
44 #ifdef CONFIG_NFS_V4_1
45 /**
46  * Per auth flavor data server rpc clients
47  */
48 struct nfs4_ds_server {
49 	struct list_head	list;   /* ds_clp->cl_ds_clients */
50 	struct rpc_clnt		*rpc_clnt;
51 };
52 
53 /**
54  * Common lookup case for DS I/O
55  */
56 static struct nfs4_ds_server *
57 nfs4_find_ds_client(struct nfs_client *ds_clp, rpc_authflavor_t flavor)
58 {
59 	struct nfs4_ds_server *dss;
60 
61 	rcu_read_lock();
62 	list_for_each_entry_rcu(dss, &ds_clp->cl_ds_clients, list) {
63 		if (dss->rpc_clnt->cl_auth->au_flavor != flavor)
64 			continue;
65 		goto out;
66 	}
67 	dss = NULL;
68 out:
69 	rcu_read_unlock();
70 	return dss;
71 }
72 
73 static struct nfs4_ds_server *
74 nfs4_add_ds_client(struct nfs_client *ds_clp, rpc_authflavor_t flavor,
75 			   struct nfs4_ds_server *new)
76 {
77 	struct nfs4_ds_server *dss;
78 
79 	spin_lock(&ds_clp->cl_lock);
80 	list_for_each_entry(dss, &ds_clp->cl_ds_clients, list) {
81 		if (dss->rpc_clnt->cl_auth->au_flavor != flavor)
82 			continue;
83 		goto out;
84 	}
85 	if (new)
86 		list_add_rcu(&new->list, &ds_clp->cl_ds_clients);
87 	dss = new;
88 out:
89 	spin_unlock(&ds_clp->cl_lock); /* need some lock to protect list */
90 	return dss;
91 }
92 
93 static struct nfs4_ds_server *
94 nfs4_alloc_ds_server(struct nfs_client *ds_clp, rpc_authflavor_t flavor)
95 {
96 	struct nfs4_ds_server *dss;
97 
98 	dss = kmalloc(sizeof(*dss), GFP_NOFS);
99 	if (dss == NULL)
100 		return ERR_PTR(-ENOMEM);
101 
102 	dss->rpc_clnt = rpc_clone_client_set_auth(ds_clp->cl_rpcclient, flavor);
103 	if (IS_ERR(dss->rpc_clnt)) {
104 		int err = PTR_ERR(dss->rpc_clnt);
105 		kfree (dss);
106 		return ERR_PTR(err);
107 	}
108 	INIT_LIST_HEAD(&dss->list);
109 
110 	return dss;
111 }
112 
113 static void
114 nfs4_free_ds_server(struct nfs4_ds_server *dss)
115 {
116 	rpc_release_client(dss->rpc_clnt);
117 	kfree(dss);
118 }
119 
120 /**
121 * Find or create a DS rpc client with th MDS server rpc client auth flavor
122 * in the nfs_client cl_ds_clients list.
123 */
124 struct rpc_clnt *
125 nfs4_find_or_create_ds_client(struct nfs_client *ds_clp, struct inode *inode)
126 {
127 	struct nfs4_ds_server *dss, *new;
128 	rpc_authflavor_t flavor = NFS_SERVER(inode)->client->cl_auth->au_flavor;
129 
130 	dss = nfs4_find_ds_client(ds_clp, flavor);
131 	if (dss != NULL)
132 		goto out;
133 	new = nfs4_alloc_ds_server(ds_clp, flavor);
134 	if (IS_ERR(new))
135 		return ERR_CAST(new);
136 	dss = nfs4_add_ds_client(ds_clp, flavor, new);
137 	if (dss != new)
138 		nfs4_free_ds_server(new);
139 out:
140 	return dss->rpc_clnt;
141 }
142 EXPORT_SYMBOL_GPL(nfs4_find_or_create_ds_client);
143 
144 static void
145 nfs4_shutdown_ds_clients(struct nfs_client *clp)
146 {
147 	struct nfs4_ds_server *dss;
148 	LIST_HEAD(shutdown_list);
149 
150 	while (!list_empty(&clp->cl_ds_clients)) {
151 		dss = list_entry(clp->cl_ds_clients.next,
152 					struct nfs4_ds_server, list);
153 		list_del(&dss->list);
154 		rpc_shutdown_client(dss->rpc_clnt);
155 		kfree (dss);
156 	}
157 }
158 
159 void nfs41_shutdown_client(struct nfs_client *clp)
160 {
161 	if (nfs4_has_session(clp)) {
162 		nfs4_shutdown_ds_clients(clp);
163 		nfs4_destroy_session(clp->cl_session);
164 		nfs4_destroy_clientid(clp);
165 	}
166 
167 }
168 #endif	/* CONFIG_NFS_V4_1 */
169 
170 void nfs40_shutdown_client(struct nfs_client *clp)
171 {
172 	if (clp->cl_slot_tbl) {
173 		nfs4_shutdown_slot_table(clp->cl_slot_tbl);
174 		kfree(clp->cl_slot_tbl);
175 	}
176 }
177 
178 struct nfs_client *nfs4_alloc_client(const struct nfs_client_initdata *cl_init)
179 {
180 	int err;
181 	struct nfs_client *clp = nfs_alloc_client(cl_init);
182 	if (IS_ERR(clp))
183 		return clp;
184 
185 	err = nfs_get_cb_ident_idr(clp, cl_init->minorversion);
186 	if (err)
187 		goto error;
188 
189 	if (cl_init->minorversion > NFS4_MAX_MINOR_VERSION) {
190 		err = -EINVAL;
191 		goto error;
192 	}
193 
194 	spin_lock_init(&clp->cl_lock);
195 	INIT_DELAYED_WORK(&clp->cl_renewd, nfs4_renew_state);
196 	INIT_LIST_HEAD(&clp->cl_ds_clients);
197 	rpc_init_wait_queue(&clp->cl_rpcwaitq, "NFS client");
198 	clp->cl_state = 1 << NFS4CLNT_LEASE_EXPIRED;
199 	clp->cl_minorversion = cl_init->minorversion;
200 	clp->cl_mvops = nfs_v4_minor_ops[cl_init->minorversion];
201 	clp->cl_mig_gen = 1;
202 	return clp;
203 
204 error:
205 	nfs_free_client(clp);
206 	return ERR_PTR(err);
207 }
208 
209 /*
210  * Destroy the NFS4 callback service
211  */
212 static void nfs4_destroy_callback(struct nfs_client *clp)
213 {
214 	if (__test_and_clear_bit(NFS_CS_CALLBACK, &clp->cl_res_state))
215 		nfs_callback_down(clp->cl_mvops->minor_version, clp->cl_net);
216 }
217 
218 static void nfs4_shutdown_client(struct nfs_client *clp)
219 {
220 	if (__test_and_clear_bit(NFS_CS_RENEWD, &clp->cl_res_state))
221 		nfs4_kill_renewd(clp);
222 	clp->cl_mvops->shutdown_client(clp);
223 	nfs4_destroy_callback(clp);
224 	if (__test_and_clear_bit(NFS_CS_IDMAP, &clp->cl_res_state))
225 		nfs_idmap_delete(clp);
226 
227 	rpc_destroy_wait_queue(&clp->cl_rpcwaitq);
228 	kfree(clp->cl_serverowner);
229 	kfree(clp->cl_serverscope);
230 	kfree(clp->cl_implid);
231 }
232 
233 void nfs4_free_client(struct nfs_client *clp)
234 {
235 	nfs4_shutdown_client(clp);
236 	nfs_free_client(clp);
237 }
238 
239 /*
240  * Initialize the NFS4 callback service
241  */
242 static int nfs4_init_callback(struct nfs_client *clp)
243 {
244 	struct rpc_xprt *xprt;
245 	int error;
246 
247 	xprt = rcu_dereference_raw(clp->cl_rpcclient->cl_xprt);
248 
249 	if (nfs4_has_session(clp)) {
250 		error = xprt_setup_backchannel(xprt, NFS41_BC_MIN_CALLBACKS);
251 		if (error < 0)
252 			return error;
253 	}
254 
255 	error = nfs_callback_up(clp->cl_mvops->minor_version, xprt);
256 	if (error < 0) {
257 		dprintk("%s: failed to start callback. Error = %d\n",
258 			__func__, error);
259 		return error;
260 	}
261 	__set_bit(NFS_CS_CALLBACK, &clp->cl_res_state);
262 
263 	return 0;
264 }
265 
266 /**
267  * nfs40_init_client - nfs_client initialization tasks for NFSv4.0
268  * @clp - nfs_client to initialize
269  *
270  * Returns zero on success, or a negative errno if some error occurred.
271  */
272 int nfs40_init_client(struct nfs_client *clp)
273 {
274 	struct nfs4_slot_table *tbl;
275 	int ret;
276 
277 	tbl = kzalloc(sizeof(*tbl), GFP_NOFS);
278 	if (tbl == NULL)
279 		return -ENOMEM;
280 
281 	ret = nfs4_setup_slot_table(tbl, NFS4_MAX_SLOT_TABLE,
282 					"NFSv4.0 transport Slot table");
283 	if (ret) {
284 		kfree(tbl);
285 		return ret;
286 	}
287 
288 	clp->cl_slot_tbl = tbl;
289 	return 0;
290 }
291 
292 #if defined(CONFIG_NFS_V4_1)
293 
294 /**
295  * nfs41_init_client - nfs_client initialization tasks for NFSv4.1+
296  * @clp - nfs_client to initialize
297  *
298  * Returns zero on success, or a negative errno if some error occurred.
299  */
300 int nfs41_init_client(struct nfs_client *clp)
301 {
302 	struct nfs4_session *session = NULL;
303 
304 	/*
305 	 * Create the session and mark it expired.
306 	 * When a SEQUENCE operation encounters the expired session
307 	 * it will do session recovery to initialize it.
308 	 */
309 	session = nfs4_alloc_session(clp);
310 	if (!session)
311 		return -ENOMEM;
312 
313 	clp->cl_session = session;
314 
315 	/*
316 	 * The create session reply races with the server back
317 	 * channel probe. Mark the client NFS_CS_SESSION_INITING
318 	 * so that the client back channel can find the
319 	 * nfs_client struct
320 	 */
321 	nfs_mark_client_ready(clp, NFS_CS_SESSION_INITING);
322 	return 0;
323 }
324 
325 #endif	/* CONFIG_NFS_V4_1 */
326 
327 /*
328  * Initialize the minor version specific parts of an NFS4 client record
329  */
330 static int nfs4_init_client_minor_version(struct nfs_client *clp)
331 {
332 	int ret;
333 
334 	ret = clp->cl_mvops->init_client(clp);
335 	if (ret)
336 		return ret;
337 	return nfs4_init_callback(clp);
338 }
339 
340 /**
341  * nfs4_init_client - Initialise an NFS4 client record
342  *
343  * @clp: nfs_client to initialise
344  * @timeparms: timeout parameters for underlying RPC transport
345  * @ip_addr: callback IP address in presentation format
346  * @authflavor: authentication flavor for underlying RPC transport
347  *
348  * Returns pointer to an NFS client, or an ERR_PTR value.
349  */
350 struct nfs_client *nfs4_init_client(struct nfs_client *clp,
351 				    const struct rpc_timeout *timeparms,
352 				    const char *ip_addr)
353 {
354 	char buf[INET6_ADDRSTRLEN + 1];
355 	struct nfs_client *old;
356 	int error;
357 
358 	if (clp->cl_cons_state == NFS_CS_READY) {
359 		/* the client is initialised already */
360 		dprintk("<-- nfs4_init_client() = 0 [already %p]\n", clp);
361 		return clp;
362 	}
363 
364 	/* Check NFS protocol revision and initialize RPC op vector */
365 	clp->rpc_ops = &nfs_v4_clientops;
366 
367 	if (clp->cl_minorversion != 0)
368 		__set_bit(NFS_CS_INFINITE_SLOTS, &clp->cl_flags);
369 	__set_bit(NFS_CS_DISCRTRY, &clp->cl_flags);
370 	__set_bit(NFS_CS_NO_RETRANS_TIMEOUT, &clp->cl_flags);
371 
372 	error = nfs_create_rpc_client(clp, timeparms, RPC_AUTH_GSS_KRB5I);
373 	if (error == -EINVAL)
374 		error = nfs_create_rpc_client(clp, timeparms, RPC_AUTH_UNIX);
375 	if (error < 0)
376 		goto error;
377 
378 	/* If no clientaddr= option was specified, find a usable cb address */
379 	if (ip_addr == NULL) {
380 		struct sockaddr_storage cb_addr;
381 		struct sockaddr *sap = (struct sockaddr *)&cb_addr;
382 
383 		error = rpc_localaddr(clp->cl_rpcclient, sap, sizeof(cb_addr));
384 		if (error < 0)
385 			goto error;
386 		error = rpc_ntop(sap, buf, sizeof(buf));
387 		if (error < 0)
388 			goto error;
389 		ip_addr = (const char *)buf;
390 	}
391 	strlcpy(clp->cl_ipaddr, ip_addr, sizeof(clp->cl_ipaddr));
392 
393 	error = nfs_idmap_new(clp);
394 	if (error < 0) {
395 		dprintk("%s: failed to create idmapper. Error = %d\n",
396 			__func__, error);
397 		goto error;
398 	}
399 	__set_bit(NFS_CS_IDMAP, &clp->cl_res_state);
400 
401 	error = nfs4_init_client_minor_version(clp);
402 	if (error < 0)
403 		goto error;
404 
405 	if (!nfs4_has_session(clp))
406 		nfs_mark_client_ready(clp, NFS_CS_READY);
407 
408 	error = nfs4_discover_server_trunking(clp, &old);
409 	if (error < 0)
410 		goto error;
411 
412 	if (clp != old)
413 		clp->cl_preserve_clid = true;
414 	nfs_put_client(clp);
415 	return old;
416 
417 error:
418 	nfs_mark_client_ready(clp, error);
419 	nfs_put_client(clp);
420 	dprintk("<-- nfs4_init_client() = xerror %d\n", error);
421 	return ERR_PTR(error);
422 }
423 
424 /*
425  * SETCLIENTID just did a callback update with the callback ident in
426  * "drop," but server trunking discovery claims "drop" and "keep" are
427  * actually the same server.  Swap the callback IDs so that "keep"
428  * will continue to use the callback ident the server now knows about,
429  * and so that "keep"'s original callback ident is destroyed when
430  * "drop" is freed.
431  */
432 static void nfs4_swap_callback_idents(struct nfs_client *keep,
433 				      struct nfs_client *drop)
434 {
435 	struct nfs_net *nn = net_generic(keep->cl_net, nfs_net_id);
436 	unsigned int save = keep->cl_cb_ident;
437 
438 	if (keep->cl_cb_ident == drop->cl_cb_ident)
439 		return;
440 
441 	dprintk("%s: keeping callback ident %u and dropping ident %u\n",
442 		__func__, keep->cl_cb_ident, drop->cl_cb_ident);
443 
444 	spin_lock(&nn->nfs_client_lock);
445 
446 	idr_replace(&nn->cb_ident_idr, keep, drop->cl_cb_ident);
447 	keep->cl_cb_ident = drop->cl_cb_ident;
448 
449 	idr_replace(&nn->cb_ident_idr, drop, save);
450 	drop->cl_cb_ident = save;
451 
452 	spin_unlock(&nn->nfs_client_lock);
453 }
454 
455 /**
456  * nfs40_walk_client_list - Find server that recognizes a client ID
457  *
458  * @new: nfs_client with client ID to test
459  * @result: OUT: found nfs_client, or new
460  * @cred: credential to use for trunking test
461  *
462  * Returns zero, a negative errno, or a negative NFS4ERR status.
463  * If zero is returned, an nfs_client pointer is planted in "result."
464  *
465  * NB: nfs40_walk_client_list() relies on the new nfs_client being
466  *     the last nfs_client on the list.
467  */
468 int nfs40_walk_client_list(struct nfs_client *new,
469 			   struct nfs_client **result,
470 			   struct rpc_cred *cred)
471 {
472 	struct nfs_net *nn = net_generic(new->cl_net, nfs_net_id);
473 	struct nfs_client *pos, *prev = NULL;
474 	struct nfs4_setclientid_res clid = {
475 		.clientid	= new->cl_clientid,
476 		.confirm	= new->cl_confirm,
477 	};
478 	int status = -NFS4ERR_STALE_CLIENTID;
479 
480 	spin_lock(&nn->nfs_client_lock);
481 	list_for_each_entry(pos, &nn->nfs_client_list, cl_share_link) {
482 
483 		if (pos->rpc_ops != new->rpc_ops)
484 			continue;
485 
486 		if (pos->cl_proto != new->cl_proto)
487 			continue;
488 
489 		if (pos->cl_minorversion != new->cl_minorversion)
490 			continue;
491 
492 		/* If "pos" isn't marked ready, we can't trust the
493 		 * remaining fields in "pos" */
494 		if (pos->cl_cons_state > NFS_CS_READY) {
495 			atomic_inc(&pos->cl_count);
496 			spin_unlock(&nn->nfs_client_lock);
497 
498 			nfs_put_client(prev);
499 			prev = pos;
500 
501 			status = nfs_wait_client_init_complete(pos);
502 			if (status < 0)
503 				goto out;
504 			status = -NFS4ERR_STALE_CLIENTID;
505 			spin_lock(&nn->nfs_client_lock);
506 		}
507 		if (pos->cl_cons_state != NFS_CS_READY)
508 			continue;
509 
510 		if (pos->cl_clientid != new->cl_clientid)
511 			continue;
512 
513 		atomic_inc(&pos->cl_count);
514 		spin_unlock(&nn->nfs_client_lock);
515 
516 		nfs_put_client(prev);
517 		prev = pos;
518 
519 		status = nfs4_proc_setclientid_confirm(pos, &clid, cred);
520 		switch (status) {
521 		case -NFS4ERR_STALE_CLIENTID:
522 			break;
523 		case 0:
524 			nfs4_swap_callback_idents(pos, new);
525 
526 			prev = NULL;
527 			*result = pos;
528 			dprintk("NFS: <-- %s using nfs_client = %p ({%d})\n",
529 				__func__, pos, atomic_read(&pos->cl_count));
530 			goto out;
531 		case -ERESTARTSYS:
532 		case -ETIMEDOUT:
533 			/* The callback path may have been inadvertently
534 			 * changed. Schedule recovery!
535 			 */
536 			nfs4_schedule_path_down_recovery(pos);
537 		default:
538 			goto out;
539 		}
540 
541 		spin_lock(&nn->nfs_client_lock);
542 	}
543 	spin_unlock(&nn->nfs_client_lock);
544 
545 	/* No match found. The server lost our clientid */
546 out:
547 	nfs_put_client(prev);
548 	dprintk("NFS: <-- %s status = %d\n", __func__, status);
549 	return status;
550 }
551 
552 #ifdef CONFIG_NFS_V4_1
553 /*
554  * Returns true if the client IDs match
555  */
556 static bool nfs4_match_clientids(struct nfs_client *a, struct nfs_client *b)
557 {
558 	if (a->cl_clientid != b->cl_clientid) {
559 		dprintk("NFS: --> %s client ID %llx does not match %llx\n",
560 			__func__, a->cl_clientid, b->cl_clientid);
561 		return false;
562 	}
563 	dprintk("NFS: --> %s client ID %llx matches %llx\n",
564 		__func__, a->cl_clientid, b->cl_clientid);
565 	return true;
566 }
567 
568 /*
569  * Returns true if the server owners match
570  */
571 static bool
572 nfs4_match_serverowners(struct nfs_client *a, struct nfs_client *b)
573 {
574 	struct nfs41_server_owner *o1 = a->cl_serverowner;
575 	struct nfs41_server_owner *o2 = b->cl_serverowner;
576 
577 	if (o1->minor_id != o2->minor_id) {
578 		dprintk("NFS: --> %s server owner minor IDs do not match\n",
579 			__func__);
580 		return false;
581 	}
582 
583 	if (o1->major_id_sz != o2->major_id_sz)
584 		goto out_major_mismatch;
585 	if (memcmp(o1->major_id, o2->major_id, o1->major_id_sz) != 0)
586 		goto out_major_mismatch;
587 
588 	dprintk("NFS: --> %s server owners match\n", __func__);
589 	return true;
590 
591 out_major_mismatch:
592 	dprintk("NFS: --> %s server owner major IDs do not match\n",
593 		__func__);
594 	return false;
595 }
596 
597 /**
598  * nfs41_walk_client_list - Find nfs_client that matches a client/server owner
599  *
600  * @new: nfs_client with client ID to test
601  * @result: OUT: found nfs_client, or new
602  * @cred: credential to use for trunking test
603  *
604  * Returns zero, a negative errno, or a negative NFS4ERR status.
605  * If zero is returned, an nfs_client pointer is planted in "result."
606  *
607  * NB: nfs41_walk_client_list() relies on the new nfs_client being
608  *     the last nfs_client on the list.
609  */
610 int nfs41_walk_client_list(struct nfs_client *new,
611 			   struct nfs_client **result,
612 			   struct rpc_cred *cred)
613 {
614 	struct nfs_net *nn = net_generic(new->cl_net, nfs_net_id);
615 	struct nfs_client *pos, *prev = NULL;
616 	int status = -NFS4ERR_STALE_CLIENTID;
617 
618 	spin_lock(&nn->nfs_client_lock);
619 	list_for_each_entry(pos, &nn->nfs_client_list, cl_share_link) {
620 
621 		if (pos->rpc_ops != new->rpc_ops)
622 			continue;
623 
624 		if (pos->cl_proto != new->cl_proto)
625 			continue;
626 
627 		if (pos->cl_minorversion != new->cl_minorversion)
628 			continue;
629 
630 		/* If "pos" isn't marked ready, we can't trust the
631 		 * remaining fields in "pos", especially the client
632 		 * ID and serverowner fields.  Wait for CREATE_SESSION
633 		 * to finish. */
634 		if (pos->cl_cons_state > NFS_CS_READY) {
635 			atomic_inc(&pos->cl_count);
636 			spin_unlock(&nn->nfs_client_lock);
637 
638 			nfs_put_client(prev);
639 			prev = pos;
640 
641 			status = nfs_wait_client_init_complete(pos);
642 			if (status == 0) {
643 				nfs4_schedule_lease_recovery(pos);
644 				status = nfs4_wait_clnt_recover(pos);
645 			}
646 			spin_lock(&nn->nfs_client_lock);
647 			if (status < 0)
648 				break;
649 			status = -NFS4ERR_STALE_CLIENTID;
650 		}
651 		if (pos->cl_cons_state != NFS_CS_READY)
652 			continue;
653 
654 		if (!nfs4_match_clientids(pos, new))
655 			continue;
656 
657 		if (!nfs4_match_serverowners(pos, new))
658 			continue;
659 
660 		atomic_inc(&pos->cl_count);
661 		*result = pos;
662 		status = 0;
663 		dprintk("NFS: <-- %s using nfs_client = %p ({%d})\n",
664 			__func__, pos, atomic_read(&pos->cl_count));
665 		break;
666 	}
667 
668 	/* No matching nfs_client found. */
669 	spin_unlock(&nn->nfs_client_lock);
670 	dprintk("NFS: <-- %s status = %d\n", __func__, status);
671 	nfs_put_client(prev);
672 	return status;
673 }
674 #endif	/* CONFIG_NFS_V4_1 */
675 
676 static void nfs4_destroy_server(struct nfs_server *server)
677 {
678 	nfs_server_return_all_delegations(server);
679 	unset_pnfs_layoutdriver(server);
680 	nfs4_purge_state_owners(server);
681 }
682 
683 /*
684  * NFSv4.0 callback thread helper
685  *
686  * Find a client by callback identifier
687  */
688 struct nfs_client *
689 nfs4_find_client_ident(struct net *net, int cb_ident)
690 {
691 	struct nfs_client *clp;
692 	struct nfs_net *nn = net_generic(net, nfs_net_id);
693 
694 	spin_lock(&nn->nfs_client_lock);
695 	clp = idr_find(&nn->cb_ident_idr, cb_ident);
696 	if (clp)
697 		atomic_inc(&clp->cl_count);
698 	spin_unlock(&nn->nfs_client_lock);
699 	return clp;
700 }
701 
702 #if defined(CONFIG_NFS_V4_1)
703 /* Common match routine for v4.0 and v4.1 callback services */
704 static bool nfs4_cb_match_client(const struct sockaddr *addr,
705 		struct nfs_client *clp, u32 minorversion)
706 {
707 	struct sockaddr *clap = (struct sockaddr *)&clp->cl_addr;
708 
709 	/* Don't match clients that failed to initialise */
710 	if (!(clp->cl_cons_state == NFS_CS_READY ||
711 	    clp->cl_cons_state == NFS_CS_SESSION_INITING))
712 		return false;
713 
714 	smp_rmb();
715 
716 	/* Match the version and minorversion */
717 	if (clp->rpc_ops->version != 4 ||
718 	    clp->cl_minorversion != minorversion)
719 		return false;
720 
721 	/* Match only the IP address, not the port number */
722 	if (!nfs_sockaddr_match_ipaddr(addr, clap))
723 		return false;
724 
725 	return true;
726 }
727 
728 /*
729  * NFSv4.1 callback thread helper
730  * For CB_COMPOUND calls, find a client by IP address, protocol version,
731  * minorversion, and sessionID
732  *
733  * Returns NULL if no such client
734  */
735 struct nfs_client *
736 nfs4_find_client_sessionid(struct net *net, const struct sockaddr *addr,
737 			   struct nfs4_sessionid *sid, u32 minorversion)
738 {
739 	struct nfs_client *clp;
740 	struct nfs_net *nn = net_generic(net, nfs_net_id);
741 
742 	spin_lock(&nn->nfs_client_lock);
743 	list_for_each_entry(clp, &nn->nfs_client_list, cl_share_link) {
744 		if (nfs4_cb_match_client(addr, clp, minorversion) == false)
745 			continue;
746 
747 		if (!nfs4_has_session(clp))
748 			continue;
749 
750 		/* Match sessionid*/
751 		if (memcmp(clp->cl_session->sess_id.data,
752 		    sid->data, NFS4_MAX_SESSIONID_LEN) != 0)
753 			continue;
754 
755 		atomic_inc(&clp->cl_count);
756 		spin_unlock(&nn->nfs_client_lock);
757 		return clp;
758 	}
759 	spin_unlock(&nn->nfs_client_lock);
760 	return NULL;
761 }
762 
763 #else /* CONFIG_NFS_V4_1 */
764 
765 struct nfs_client *
766 nfs4_find_client_sessionid(struct net *net, const struct sockaddr *addr,
767 			   struct nfs4_sessionid *sid, u32 minorversion)
768 {
769 	return NULL;
770 }
771 #endif /* CONFIG_NFS_V4_1 */
772 
773 /*
774  * Set up an NFS4 client
775  */
776 static int nfs4_set_client(struct nfs_server *server,
777 		const char *hostname,
778 		const struct sockaddr *addr,
779 		const size_t addrlen,
780 		const char *ip_addr,
781 		rpc_authflavor_t authflavour,
782 		int proto, const struct rpc_timeout *timeparms,
783 		u32 minorversion, struct net *net)
784 {
785 	struct nfs_client_initdata cl_init = {
786 		.hostname = hostname,
787 		.addr = addr,
788 		.addrlen = addrlen,
789 		.nfs_mod = &nfs_v4,
790 		.proto = proto,
791 		.minorversion = minorversion,
792 		.net = net,
793 	};
794 	struct nfs_client *clp;
795 	int error;
796 
797 	dprintk("--> nfs4_set_client()\n");
798 
799 	if (server->flags & NFS_MOUNT_NORESVPORT)
800 		set_bit(NFS_CS_NORESVPORT, &cl_init.init_flags);
801 	if (server->options & NFS_OPTION_MIGRATION)
802 		set_bit(NFS_CS_MIGRATION, &cl_init.init_flags);
803 
804 	/* Allocate or find a client reference we can use */
805 	clp = nfs_get_client(&cl_init, timeparms, ip_addr, authflavour);
806 	if (IS_ERR(clp)) {
807 		error = PTR_ERR(clp);
808 		goto error;
809 	}
810 
811 	/*
812 	 * Query for the lease time on clientid setup or renewal
813 	 *
814 	 * Note that this will be set on nfs_clients that were created
815 	 * only for the DS role and did not set this bit, but now will
816 	 * serve a dual role.
817 	 */
818 	set_bit(NFS_CS_CHECK_LEASE_TIME, &clp->cl_res_state);
819 
820 	server->nfs_client = clp;
821 	dprintk("<-- nfs4_set_client() = 0 [new %p]\n", clp);
822 	return 0;
823 error:
824 	dprintk("<-- nfs4_set_client() = xerror %d\n", error);
825 	return error;
826 }
827 
828 /*
829  * Set up a pNFS Data Server client.
830  *
831  * Return any existing nfs_client that matches server address,port,version
832  * and minorversion.
833  *
834  * For a new nfs_client, use a soft mount (default), a low retrans and a
835  * low timeout interval so that if a connection is lost, we retry through
836  * the MDS.
837  */
838 struct nfs_client *nfs4_set_ds_client(struct nfs_client* mds_clp,
839 		const struct sockaddr *ds_addr, int ds_addrlen,
840 		int ds_proto, unsigned int ds_timeo, unsigned int ds_retrans)
841 {
842 	struct nfs_client_initdata cl_init = {
843 		.addr = ds_addr,
844 		.addrlen = ds_addrlen,
845 		.nfs_mod = &nfs_v4,
846 		.proto = ds_proto,
847 		.minorversion = mds_clp->cl_minorversion,
848 		.net = mds_clp->cl_net,
849 	};
850 	struct rpc_timeout ds_timeout;
851 	struct nfs_client *clp;
852 	char buf[INET6_ADDRSTRLEN + 1];
853 
854 	if (rpc_ntop(ds_addr, buf, sizeof(buf)) <= 0)
855 		return ERR_PTR(-EINVAL);
856 	cl_init.hostname = buf;
857 
858 	/*
859 	 * Set an authflavor equual to the MDS value. Use the MDS nfs_client
860 	 * cl_ipaddr so as to use the same EXCHANGE_ID co_ownerid as the MDS
861 	 * (section 13.1 RFC 5661).
862 	 */
863 	nfs_init_timeout_values(&ds_timeout, ds_proto, ds_timeo, ds_retrans);
864 	clp = nfs_get_client(&cl_init, &ds_timeout, mds_clp->cl_ipaddr,
865 			     mds_clp->cl_rpcclient->cl_auth->au_flavor);
866 
867 	dprintk("<-- %s %p\n", __func__, clp);
868 	return clp;
869 }
870 EXPORT_SYMBOL_GPL(nfs4_set_ds_client);
871 
872 /*
873  * Session has been established, and the client marked ready.
874  * Set the mount rsize and wsize with negotiated fore channel
875  * attributes which will be bound checked in nfs_server_set_fsinfo.
876  */
877 static void nfs4_session_set_rwsize(struct nfs_server *server)
878 {
879 #ifdef CONFIG_NFS_V4_1
880 	struct nfs4_session *sess;
881 	u32 server_resp_sz;
882 	u32 server_rqst_sz;
883 
884 	if (!nfs4_has_session(server->nfs_client))
885 		return;
886 	sess = server->nfs_client->cl_session;
887 	server_resp_sz = sess->fc_attrs.max_resp_sz - nfs41_maxread_overhead;
888 	server_rqst_sz = sess->fc_attrs.max_rqst_sz - nfs41_maxwrite_overhead;
889 
890 	if (server->rsize > server_resp_sz)
891 		server->rsize = server_resp_sz;
892 	if (server->wsize > server_rqst_sz)
893 		server->wsize = server_rqst_sz;
894 #endif /* CONFIG_NFS_V4_1 */
895 }
896 
897 static int nfs4_server_common_setup(struct nfs_server *server,
898 		struct nfs_fh *mntfh, bool auth_probe)
899 {
900 	struct nfs_fattr *fattr;
901 	int error;
902 
903 	/* data servers support only a subset of NFSv4.1 */
904 	if (is_ds_only_client(server->nfs_client))
905 		return -EPROTONOSUPPORT;
906 
907 	fattr = nfs_alloc_fattr();
908 	if (fattr == NULL)
909 		return -ENOMEM;
910 
911 	/* We must ensure the session is initialised first */
912 	error = nfs4_init_session(server->nfs_client);
913 	if (error < 0)
914 		goto out;
915 
916 	/* Set the basic capabilities */
917 	server->caps |= server->nfs_client->cl_mvops->init_caps;
918 	if (server->flags & NFS_MOUNT_NORDIRPLUS)
919 			server->caps &= ~NFS_CAP_READDIRPLUS;
920 	/*
921 	 * Don't use NFS uid/gid mapping if we're using AUTH_SYS or lower
922 	 * authentication.
923 	 */
924 	if (nfs4_disable_idmapping &&
925 			server->client->cl_auth->au_flavor == RPC_AUTH_UNIX)
926 		server->caps |= NFS_CAP_UIDGID_NOMAP;
927 
928 
929 	/* Probe the root fh to retrieve its FSID and filehandle */
930 	error = nfs4_get_rootfh(server, mntfh, auth_probe);
931 	if (error < 0)
932 		goto out;
933 
934 	dprintk("Server FSID: %llx:%llx\n",
935 			(unsigned long long) server->fsid.major,
936 			(unsigned long long) server->fsid.minor);
937 	nfs_display_fhandle(mntfh, "Pseudo-fs root FH");
938 
939 	nfs4_session_set_rwsize(server);
940 
941 	error = nfs_probe_fsinfo(server, mntfh, fattr);
942 	if (error < 0)
943 		goto out;
944 
945 	if (server->namelen == 0 || server->namelen > NFS4_MAXNAMLEN)
946 		server->namelen = NFS4_MAXNAMLEN;
947 
948 	nfs_server_insert_lists(server);
949 	server->mount_time = jiffies;
950 	server->destroy = nfs4_destroy_server;
951 out:
952 	nfs_free_fattr(fattr);
953 	return error;
954 }
955 
956 /*
957  * Create a version 4 volume record
958  */
959 static int nfs4_init_server(struct nfs_server *server,
960 		struct nfs_parsed_mount_data *data)
961 {
962 	struct rpc_timeout timeparms;
963 	int error;
964 
965 	dprintk("--> nfs4_init_server()\n");
966 
967 	nfs_init_timeout_values(&timeparms, data->nfs_server.protocol,
968 			data->timeo, data->retrans);
969 
970 	/* Initialise the client representation from the mount data */
971 	server->flags = data->flags;
972 	server->options = data->options;
973 	server->auth_info = data->auth_info;
974 
975 	/* Use the first specified auth flavor. If this flavor isn't
976 	 * allowed by the server, use the SECINFO path to try the
977 	 * other specified flavors */
978 	if (data->auth_info.flavor_len >= 1)
979 		data->selected_flavor = data->auth_info.flavors[0];
980 	else
981 		data->selected_flavor = RPC_AUTH_UNIX;
982 
983 	/* Get a client record */
984 	error = nfs4_set_client(server,
985 			data->nfs_server.hostname,
986 			(const struct sockaddr *)&data->nfs_server.address,
987 			data->nfs_server.addrlen,
988 			data->client_address,
989 			data->selected_flavor,
990 			data->nfs_server.protocol,
991 			&timeparms,
992 			data->minorversion,
993 			data->net);
994 	if (error < 0)
995 		goto error;
996 
997 	if (data->rsize)
998 		server->rsize = nfs_block_size(data->rsize, NULL);
999 	if (data->wsize)
1000 		server->wsize = nfs_block_size(data->wsize, NULL);
1001 
1002 	server->acregmin = data->acregmin * HZ;
1003 	server->acregmax = data->acregmax * HZ;
1004 	server->acdirmin = data->acdirmin * HZ;
1005 	server->acdirmax = data->acdirmax * HZ;
1006 
1007 	server->port = data->nfs_server.port;
1008 
1009 	error = nfs_init_server_rpcclient(server, &timeparms,
1010 					  data->selected_flavor);
1011 
1012 error:
1013 	/* Done */
1014 	dprintk("<-- nfs4_init_server() = %d\n", error);
1015 	return error;
1016 }
1017 
1018 /*
1019  * Create a version 4 volume record
1020  * - keyed on server and FSID
1021  */
1022 /*struct nfs_server *nfs4_create_server(const struct nfs_parsed_mount_data *data,
1023 				      struct nfs_fh *mntfh)*/
1024 struct nfs_server *nfs4_create_server(struct nfs_mount_info *mount_info,
1025 				      struct nfs_subversion *nfs_mod)
1026 {
1027 	struct nfs_server *server;
1028 	bool auth_probe;
1029 	int error;
1030 
1031 	dprintk("--> nfs4_create_server()\n");
1032 
1033 	server = nfs_alloc_server();
1034 	if (!server)
1035 		return ERR_PTR(-ENOMEM);
1036 
1037 	auth_probe = mount_info->parsed->auth_info.flavor_len < 1;
1038 
1039 	/* set up the general RPC client */
1040 	error = nfs4_init_server(server, mount_info->parsed);
1041 	if (error < 0)
1042 		goto error;
1043 
1044 	error = nfs4_server_common_setup(server, mount_info->mntfh, auth_probe);
1045 	if (error < 0)
1046 		goto error;
1047 
1048 	dprintk("<-- nfs4_create_server() = %p\n", server);
1049 	return server;
1050 
1051 error:
1052 	nfs_free_server(server);
1053 	dprintk("<-- nfs4_create_server() = error %d\n", error);
1054 	return ERR_PTR(error);
1055 }
1056 
1057 /*
1058  * Create an NFS4 referral server record
1059  */
1060 struct nfs_server *nfs4_create_referral_server(struct nfs_clone_mount *data,
1061 					       struct nfs_fh *mntfh)
1062 {
1063 	struct nfs_client *parent_client;
1064 	struct nfs_server *server, *parent_server;
1065 	bool auth_probe;
1066 	int error;
1067 
1068 	dprintk("--> nfs4_create_referral_server()\n");
1069 
1070 	server = nfs_alloc_server();
1071 	if (!server)
1072 		return ERR_PTR(-ENOMEM);
1073 
1074 	parent_server = NFS_SB(data->sb);
1075 	parent_client = parent_server->nfs_client;
1076 
1077 	/* Initialise the client representation from the parent server */
1078 	nfs_server_copy_userdata(server, parent_server);
1079 
1080 	/* Get a client representation.
1081 	 * Note: NFSv4 always uses TCP, */
1082 	error = nfs4_set_client(server, data->hostname,
1083 				data->addr,
1084 				data->addrlen,
1085 				parent_client->cl_ipaddr,
1086 				data->authflavor,
1087 				rpc_protocol(parent_server->client),
1088 				parent_server->client->cl_timeout,
1089 				parent_client->cl_mvops->minor_version,
1090 				parent_client->cl_net);
1091 	if (error < 0)
1092 		goto error;
1093 
1094 	error = nfs_init_server_rpcclient(server, parent_server->client->cl_timeout, data->authflavor);
1095 	if (error < 0)
1096 		goto error;
1097 
1098 	auth_probe = parent_server->auth_info.flavor_len < 1;
1099 
1100 	error = nfs4_server_common_setup(server, mntfh, auth_probe);
1101 	if (error < 0)
1102 		goto error;
1103 
1104 	dprintk("<-- nfs_create_referral_server() = %p\n", server);
1105 	return server;
1106 
1107 error:
1108 	nfs_free_server(server);
1109 	dprintk("<-- nfs4_create_referral_server() = error %d\n", error);
1110 	return ERR_PTR(error);
1111 }
1112 
1113 /*
1114  * Grab the destination's particulars, including lease expiry time.
1115  *
1116  * Returns zero if probe succeeded and retrieved FSID matches the FSID
1117  * we have cached.
1118  */
1119 static int nfs_probe_destination(struct nfs_server *server)
1120 {
1121 	struct inode *inode = server->super->s_root->d_inode;
1122 	struct nfs_fattr *fattr;
1123 	int error;
1124 
1125 	fattr = nfs_alloc_fattr();
1126 	if (fattr == NULL)
1127 		return -ENOMEM;
1128 
1129 	/* Sanity: the probe won't work if the destination server
1130 	 * does not recognize the migrated FH. */
1131 	error = nfs_probe_fsinfo(server, NFS_FH(inode), fattr);
1132 
1133 	nfs_free_fattr(fattr);
1134 	return error;
1135 }
1136 
1137 /**
1138  * nfs4_update_server - Move an nfs_server to a different nfs_client
1139  *
1140  * @server: represents FSID to be moved
1141  * @hostname: new end-point's hostname
1142  * @sap: new end-point's socket address
1143  * @salen: size of "sap"
1144  * @net: net namespace
1145  *
1146  * The nfs_server must be quiescent before this function is invoked.
1147  * Either its session is drained (NFSv4.1+), or its transport is
1148  * plugged and drained (NFSv4.0).
1149  *
1150  * Returns zero on success, or a negative errno value.
1151  */
1152 int nfs4_update_server(struct nfs_server *server, const char *hostname,
1153 		       struct sockaddr *sap, size_t salen, struct net *net)
1154 {
1155 	struct nfs_client *clp = server->nfs_client;
1156 	struct rpc_clnt *clnt = server->client;
1157 	struct xprt_create xargs = {
1158 		.ident		= clp->cl_proto,
1159 		.net		= net,
1160 		.dstaddr	= sap,
1161 		.addrlen	= salen,
1162 		.servername	= hostname,
1163 	};
1164 	char buf[INET6_ADDRSTRLEN + 1];
1165 	struct sockaddr_storage address;
1166 	struct sockaddr *localaddr = (struct sockaddr *)&address;
1167 	int error;
1168 
1169 	dprintk("--> %s: move FSID %llx:%llx to \"%s\")\n", __func__,
1170 			(unsigned long long)server->fsid.major,
1171 			(unsigned long long)server->fsid.minor,
1172 			hostname);
1173 
1174 	error = rpc_switch_client_transport(clnt, &xargs, clnt->cl_timeout);
1175 	if (error != 0) {
1176 		dprintk("<-- %s(): rpc_switch_client_transport returned %d\n",
1177 			__func__, error);
1178 		goto out;
1179 	}
1180 
1181 	error = rpc_localaddr(clnt, localaddr, sizeof(address));
1182 	if (error != 0) {
1183 		dprintk("<-- %s(): rpc_localaddr returned %d\n",
1184 			__func__, error);
1185 		goto out;
1186 	}
1187 
1188 	error = -EAFNOSUPPORT;
1189 	if (rpc_ntop(localaddr, buf, sizeof(buf)) == 0) {
1190 		dprintk("<-- %s(): rpc_ntop returned %d\n",
1191 			__func__, error);
1192 		goto out;
1193 	}
1194 
1195 	nfs_server_remove_lists(server);
1196 	error = nfs4_set_client(server, hostname, sap, salen, buf,
1197 				clp->cl_rpcclient->cl_auth->au_flavor,
1198 				clp->cl_proto, clnt->cl_timeout,
1199 				clp->cl_minorversion, net);
1200 	nfs_put_client(clp);
1201 	if (error != 0) {
1202 		nfs_server_insert_lists(server);
1203 		dprintk("<-- %s(): nfs4_set_client returned %d\n",
1204 			__func__, error);
1205 		goto out;
1206 	}
1207 
1208 	if (server->nfs_client->cl_hostname == NULL)
1209 		server->nfs_client->cl_hostname = kstrdup(hostname, GFP_KERNEL);
1210 	nfs_server_insert_lists(server);
1211 
1212 	error = nfs_probe_destination(server);
1213 	if (error < 0)
1214 		goto out;
1215 
1216 	dprintk("<-- %s() succeeded\n", __func__);
1217 
1218 out:
1219 	return error;
1220 }
1221